gpt-auto: fix ESP options and description

Since 59512f21 the parameters were passed in the wrong order, causing the
options to be interpreted as the description.

Also, while "false" was supposed to be passed for "rw", the ESP should actually
be mounted read-write. It just happened to be "true" since the description char*
was passed for "rw".

src/gpt-auto-generator/gpt-auto-generator.c

@@ -526,9 +526,9 @@ static int add_boot(const char *what) {
                        what,
                        "/boot",
                        "vfat",
-                       "EFI System Partition Automount",
-                       false,
+                       true,
                        "umask=0077",
+                       "EFI System Partition Automount",
                        120 * USEC_PER_SEC);
 
         return r;