various: do not include file names directly in error messages

git grep -l 'Failed to open /'|xargs sed -r -i 's|"Failed to open (/[^ ]+): %m"|"Failed to open %s: %m", "\1"|g'
git grep -l $'Failed to open \'/'|xargs sed -r -i $'s|"Failed to open \'(/[^ ]+)\': %m"|"Failed to open %s: %m", "\\1"|g'
git grep -l "Failed to open /"|xargs sed -r -i $'s|"Failed to open (/[^ ]+), ignoring: %m"|"Failed to open %s, ignoring: %m", "\\1"|g'
+ some manual fixups.

src/network/networkctl-misc.c

@@ -292,7 +292,7 @@ int verb_persistent_storage(int argc, char *argv[], void *userdata) {
 
                 fd = open("/var/lib/systemd/network/", O_CLOEXEC | O_DIRECTORY);
                 if (fd < 0)
-                        return log_error_errno(errno, "Failed to open /var/lib/systemd/network/: %m");
+                        return log_error_errno(errno, "Failed to open %s: %m", "/var/lib/systemd/network/");
 
                 r = sd_varlink_push_fd(vl, fd);
                 if (r < 0)

src/network/networkd-manager.c

@@ -599,7 +599,7 @@ static int persistent_storage_open(void) {
 
         fd = open("/var/lib/systemd/network/", O_CLOEXEC | O_DIRECTORY);
         if (fd < 0)
-                return log_debug_errno(errno, "Failed to open /var/lib/systemd/network/, ignoring: %m");
+                return log_debug_errno(errno, "Failed to open %s, ignoring: %m", "/var/lib/systemd/network/");
 
         r = fd_is_read_only_fs(fd);
         if (r < 0)