basic: fix error/memleak in socket-util

Probably a typo, checking 'ret' instead of the return value 'p'. This
might cause the function to return failure, even though it succeeded.
Furthermore, it might leak resources.

src/basic/socket-util.c

@@ -583,7 +583,7 @@ int sockaddr_pretty(const struct sockaddr *_sa, socklen_t salen, bool translate_
 
                 } else {
                         p = strndup(sa->un.sun_path, sizeof(sa->un.sun_path));
-                        if (!ret)
+                        if (!p)
                                 return -ENOMEM;
                 }