tree-wide: make use of log_error_errno() return value

Turns this:

        r = -errno;
        log_error_errno(errno, "foo");

into this:

        r = log_error_errno(errno, "foo");

and this:

        r = log_error_errno(errno, "foo");
        return r;

into this:

        return log_error_errno(errno, "foo");

coccinelle/errno.cocci

@@ -0,0 +1,42 @@
+@@
+identifier r;
+expression t, e;
+@@
+- r = -e;
+- log_error_errno(e, t);
++ r = log_error_errno(e, t);
+@@
+identifier r;
+expression t, e;
+@@
+- log_error_errno(e, t);
+- r = -e;
++ r = log_error_errno(e, t);
+@@
+identifier r;
+expression t, e;
+@@
+- r = log_error_errno(e, t);
+- return r;
++ return log_error_errno(e, t);
+@@
+identifier r;
+expression t, e;
+@@
+- r = -e;
+- log_warning_errno(e, t);
++ r = log_warning_errno(e, t);
+@@
+identifier r;
+expression t, e;
+@@
+- log_warning_errno(e, t);
+- r = -e;
++ r = log_warning_errno(e, t);
+@@
+identifier r;
+expression t, e;
+@@
+- r = log_warning_errno(e, t);
+- return r;
++ return log_warning_errno(e, t);

src/core/execute.c

@@ -928,8 +928,7 @@ fail:
                 log_error("PAM failed: %s", pam_strerror(handle, pam_code));
                 err = -EPERM;  /* PAM errors do not map to errno */
         } else {
-                log_error_errno(errno, "PAM failed: %m");
-                err = -errno;
+                err = log_error_errno(errno, "PAM failed: %m");
         }
 
         if (handle) {

src/core/namespace.c

@@ -288,8 +288,7 @@ static int mount_kdbus(BindMount *m) {
         /* create a new /dev/null dev node copy so we have some fodder to
          * bind-mount the custom endpoint over. */
         if (stat("/dev/null", &st) < 0) {
-                log_error_errno(errno, "Failed to stat /dev/null: %m");
-                r = -errno;
+                r = log_error_errno(errno, "Failed to stat /dev/null: %m");
                 goto fail;
         }
 

src/core/shutdown.c

@@ -404,8 +404,7 @@ int main(int argc, char *argv[]) {
                 exit(0);
         }
 
-        log_error_errno(errno, "Failed to invoke reboot(): %m");
-        r = -errno;
+        r = log_error_errno(errno, "Failed to invoke reboot(): %m");
 
   error:
         log_emergency_errno(r, "Critical error while doing system shutdown: %m");

src/initctl/initctl.c

@@ -269,8 +269,8 @@ static int server_init(Server *s, unsigned n_sockets) {
 
         s->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
         if (s->epoll_fd < 0) {
-                r = -errno;
-                log_error_errno(errno, "Failed to create epoll object: %m");
+                r = log_error_errno(errno,
+                                    "Failed to create epoll object: %m");
                 goto fail;
         }
 

src/journal-remote/journal-remote.c

@@ -88,8 +88,7 @@ static int spawn_child(const char* child, char** argv) {
 
         child_pid = fork();
         if (child_pid < 0) {
-                r = -errno;
-                log_error_errno(errno, "Failed to fork: %m");
+                r = log_error_errno(errno, "Failed to fork: %m");
                 safe_close_pair(fd);
                 return r;
         }

src/journal/cat.c

@@ -142,8 +142,7 @@ int main(int argc, char *argv[]) {
 
         if (dup3(fd, STDOUT_FILENO, 0) < 0 ||
             dup3(fd, STDERR_FILENO, 0) < 0) {
-                log_error_errno(errno, "Failed to duplicate fd: %m");
-                r = -errno;
+                r = log_error_errno(errno, "Failed to duplicate fd: %m");
                 goto finish;
         }
 

src/journal/coredumpctl.c

@@ -631,8 +631,8 @@ static int save_core(sd_journal *j, int fd, char **path, bool *unlink_temp) {
 
                         sz = write(fdt, data, len);
                         if (sz < 0) {
-                                log_error_errno(errno, "Failed to write temporary file: %m");
-                                r = -errno;
+                                r = log_error_errno(errno,
+                                                    "Failed to write temporary file: %m");
                                 goto error;
                         }
                         if (sz != (ssize_t) len) {
@@ -758,8 +758,7 @@ static int run_gdb(sd_journal *j) {
 
         pid = fork();
         if (pid < 0) {
-                log_error_errno(errno, "Failed to fork(): %m");
-                r = -errno;
+                r = log_error_errno(errno, "Failed to fork(): %m");
                 goto finish;
         }
         if (pid == 0) {

src/journal/journal-verify.c

@@ -839,22 +839,20 @@ int journal_file_verify(
 
         data_fd = open_tmpfile("/var/tmp", O_RDWR | O_CLOEXEC);
         if (data_fd < 0) {
-                log_error_errno(errno, "Failed to create data file: %m");
-                r = -errno;
+                r = log_error_errno(errno, "Failed to create data file: %m");
                 goto fail;
         }
 
         entry_fd = open_tmpfile("/var/tmp", O_RDWR | O_CLOEXEC);
         if (entry_fd < 0) {
-                log_error_errno(errno, "Failed to create entry file: %m");
-                r = -errno;
+                r = log_error_errno(errno, "Failed to create entry file: %m");
                 goto fail;
         }
 
         entry_array_fd = open_tmpfile("/var/tmp", O_RDWR | O_CLOEXEC);
         if (entry_array_fd < 0) {
-                log_error_errno(errno, "Failed to create entry array file: %m");
-                r = -errno;
+                r = log_error_errno(errno,
+                                    "Failed to create entry array file: %m");
                 goto fail;
         }
 

src/journal/journalctl.c

@@ -1428,8 +1428,7 @@ static int setup_keys(void) {
 
         fd = open("/dev/random", O_RDONLY|O_CLOEXEC|O_NOCTTY);
         if (fd < 0) {
-                log_error_errno(errno, "Failed to open /dev/random: %m");
-                r = -errno;
+                r = log_error_errno(errno, "Failed to open /dev/random: %m");
                 goto finish;
         }
 
@@ -1488,8 +1487,7 @@ static int setup_keys(void) {
         }
 
         if (link(k, p) < 0) {
-                log_error_errno(errno, "Failed to link file: %m");
-                r = -errno;
+                r = log_error_errno(errno, "Failed to link file: %m");
                 goto finish;
         }
 

src/login/logind-button.c

@@ -248,8 +248,7 @@ int button_open(Button *b) {
                 return log_warning_errno(errno, "Failed to open %s: %m", b->name);
 
         if (ioctl(b->fd, EVIOCGNAME(sizeof(name)), name) < 0) {
-                log_error_errno(errno, "Failed to get input name: %m");
-                r = -errno;
+                r = log_error_errno(errno, "Failed to get input name: %m");
                 goto fail;
         }
 

src/resolve/resolved-manager.c

@@ -619,8 +619,7 @@ int manager_read_resolv_conf(Manager *m) {
         }
 
         if (fstat(fileno(f), &st) < 0) {
-                log_error_errno(errno, "Failed to stat open file: %m");
-                r = -errno;
+                r = log_error_errno(errno, "Failed to stat open file: %m");
                 goto clear;
         }
 

src/shared/ask-password-api.c

@@ -331,8 +331,8 @@ int ask_password_agent(
 
         fd = mkostemp_safe(temp, O_WRONLY|O_CLOEXEC);
         if (fd < 0) {
-                log_error_errno(errno, "Failed to create password file: %m");
-                r = -errno;
+                r = log_error_errno(errno,
+                                    "Failed to create password file: %m");
                 goto finish;
         }
 
@@ -340,8 +340,7 @@ int ask_password_agent(
 
         f = fdopen(fd, "w");
         if (!f) {
-                log_error_errno(errno, "Failed to allocate FILE: %m");
-                r = -errno;
+                r = log_error_errno(errno, "Failed to allocate FILE: %m");
                 goto finish;
         }
 
@@ -349,8 +348,7 @@ int ask_password_agent(
 
         signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
         if (signal_fd < 0) {
-                log_error_errno(errno, "signalfd(): %m");
-                r = -errno;
+                r = log_error_errno(errno, "signalfd(): %m");
                 goto finish;
         }
 
@@ -395,8 +393,7 @@ int ask_password_agent(
         final[sizeof(final)-9] = 'k';
 
         if (rename(temp, final) < 0) {
-                log_error_errno(errno, "Failed to rename query file: %m");
-                r = -errno;
+                r = log_error_errno(errno, "Failed to rename query file: %m");
                 goto finish;
         }
 
@@ -432,8 +429,7 @@ int ask_password_agent(
                         if (errno == EINTR)
                                 continue;
 
-                        log_error_errno(errno, "poll() failed: %m");
-                        r = -errno;
+                        r = log_error_errno(errno, "poll() failed: %m");
                         goto finish;
                 }
 
@@ -471,8 +467,7 @@ int ask_password_agent(
                             errno == EINTR)
                                 continue;
 
-                        log_error_errno(errno, "recvmsg() failed: %m");
-                        r = -errno;
+                        r = log_error_errno(errno, "recvmsg() failed: %m");
                         goto finish;
                 }
 

src/shared/pager.c

@@ -74,8 +74,7 @@ int pager_open(bool jump_to_end) {
 
         pager_pid = fork();
         if (pager_pid < 0) {
-                r = -errno;
-                log_error_errno(errno, "Failed to fork pager: %m");
+                r = log_error_errno(errno, "Failed to fork pager: %m");
                 safe_close_pair(fd);
                 return r;
         }

src/udev/udev-ctrl.c

@@ -122,16 +122,12 @@ int udev_ctrl_enable_receiving(struct udev_ctrl *uctrl) {
                 }
 
                 if (err < 0) {
-                        err = -errno;
-                        log_error_errno(errno, "bind failed: %m");
-                        return err;
+                        return log_error_errno(errno, "bind failed: %m");
                 }
 
                 err = listen(uctrl->sock, 0);
                 if (err < 0) {
-                        err = -errno;
-                        log_error_errno(errno, "listen failed: %m");
-                        return err;
+                        return log_error_errno(errno, "listen failed: %m");
                 }
 
                 uctrl->bound = true;

src/udev/udev-event.c

@@ -731,15 +731,13 @@ int udev_event_spawn(struct udev_event *event,
         /* pipes from child to parent */
         if (result != NULL || log_get_max_level() >= LOG_INFO) {
                 if (pipe2(outpipe, O_NONBLOCK) != 0) {
-                        err = -errno;
-                        log_error_errno(errno, "pipe failed: %m");
+                        err = log_error_errno(errno, "pipe failed: %m");
                         goto out;
                 }
         }
         if (log_get_max_level() >= LOG_INFO) {
                 if (pipe2(errpipe, O_NONBLOCK) != 0) {
-                        err = -errno;
-                        log_error_errno(errno, "pipe failed: %m");
+                        err = log_error_errno(errno, "pipe failed: %m");
                         goto out;
                 }
         }

src/update-utmp/update-utmp.c

@@ -130,8 +130,8 @@ static int on_reboot(Context *c) {
         if (c->audit_fd >= 0)
                 if (audit_log_user_comm_message(c->audit_fd, AUDIT_SYSTEM_BOOT, "", "systemd-update-utmp", NULL, NULL, NULL, 1) < 0 &&
                     errno != EPERM) {
-                        log_error_errno(errno, "Failed to send audit message: %m");
-                        r = -errno;
+                        r = log_error_errno(errno,
+                                            "Failed to send audit message: %m");
                 }
 #endif
 
@@ -160,8 +160,8 @@ static int on_shutdown(Context *c) {
         if (c->audit_fd >= 0)
                 if (audit_log_user_comm_message(c->audit_fd, AUDIT_SYSTEM_SHUTDOWN, "", "systemd-update-utmp", NULL, NULL, NULL, 1) < 0 &&
                     errno != EPERM) {
-                        log_error_errno(errno, "Failed to send audit message: %m");
-                        r = -errno;
+                        r = log_error_errno(errno,
+                                            "Failed to send audit message: %m");
                 }
 #endif
 
@@ -212,8 +212,8 @@ static int on_runlevel(Context *c) {
 
                 if (audit_log_user_comm_message(c->audit_fd, AUDIT_SYSTEM_RUNLEVEL, s, "systemd-update-utmp", NULL, NULL, NULL, 1) < 0 &&
                     errno != EPERM) {
-                        log_error_errno(errno, "Failed to send audit message: %m");
-                        r = -errno;
+                        r = log_error_errno(errno,
+                                            "Failed to send audit message: %m");
                 }
         }
 #endif

src/user-sessions/user-sessions.c

@@ -43,8 +43,8 @@ int main(int argc, char*argv[]) {
                 int r = 0;
 
                 if (unlink("/run/nologin") < 0 && errno != ENOENT) {
-                        log_error_errno(errno, "Failed to remove /run/nologin file: %m");
-                        r = -errno;
+                        r = log_error_errno(errno,
+                                            "Failed to remove /run/nologin file: %m");
                 }
 
                 if (unlink("/etc/nologin") < 0 && errno != ENOENT) {