tree-wide: propagate the error we got from strv_extend_xyz() to the caller

It's a bit sloppy to return -ENOMEM rather than the actual error we
already returned in the first place (even though it's always going to be
ENOMEM)

src/core/dbus-execute.c

@@ -1949,7 +1949,7 @@ int bus_exec_context_set_transient_property(
 
                                 r = strv_extend_strv(&c->supplementary_groups, l, true);
                                 if (r < 0)
-                                        return -ENOMEM;
+                                        return r;
 
                                 joined = strv_join(c->supplementary_groups, " ");
                                 if (!joined)
@@ -3174,7 +3174,7 @@ int bus_exec_context_set_transient_property(
 
                                 r = strv_extend_strv(dirs, l, true);
                                 if (r < 0)
-                                        return -ENOMEM;
+                                        return r;
 
                                 unit_write_settingf(u, flags, name, "%s=%s", name, joined);
                         }
@@ -3201,7 +3201,7 @@ int bus_exec_context_set_transient_property(
                                 _cleanup_free_ char *joined = NULL;
                                 r = strv_extend_strv(&c->exec_search_path, l, true);
                                 if (r < 0)
-                                        return -ENOMEM;
+                                        return r;
                                 joined = strv_join(c->exec_search_path, ":");
                                 if (!joined)
                                         return log_oom();

src/core/manager-serialize.c

@@ -494,8 +494,9 @@ int manager_deserialize(Manager *m, FILE *f, FDSet *fds) {
                         (void) exec_shared_runtime_deserialize_one(m, val, fds);
                 else if ((val = startswith(l, "subscribed="))) {
 
-                        if (strv_extend(&m->deserialized_subscribed, val) < 0)
-                                return -ENOMEM;
+                        r = strv_extend(&m->deserialized_subscribed, val);
+                        if (r < 0)
+                                return r;
                 } else if ((val = startswith(l, "varlink-server-socket-address="))) {
                         if (!m->varlink_server && MANAGER_IS_SYSTEM(m)) {
                                 r = manager_varlink_init(m);

src/core/service.c

@@ -3098,7 +3098,7 @@ int service_deserialize_exec_command(
                 case STATE_EXEC_COMMAND_ARGS:
                         r = strv_extend(&argv, arg);
                         if (r < 0)
-                                return -ENOMEM;
+                                return r;
                         break;
                 default:
                         assert_not_reached();