tree-wide: propagate error code from _from_string() functions

Now that we know we have something useful, no need to make an answer up.

src/systemctl/systemctl-log-setting.c

@@ -30,9 +30,9 @@ static int log_setting_internal(sd_bus *bus, const BusLocator* bloc, const char
 
         if (value) {
                 if (level) {
-                        if (log_level_from_string(value) < 0)
-                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
-                                                       "\"%s\" is not a valid log level.", value);
+                        r = log_level_from_string(value);
+                        if (r < 0)
+                                return log_error_errno(r, "\"%s\" is not a valid log level.", value);
                 }
 
                 r = bus_set_property(bus, bloc,

src/systemctl/systemctl-show.c

@@ -2040,8 +2040,7 @@ int show(int argc, char *argv[], void *userdata) {
 
         show_mode = systemctl_show_mode_from_string(argv[0]);
         if (show_mode < 0)
-                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
-                                       "Invalid argument.");
+                return log_error_errno(show_mode, "Invalid argument.");
 
         if (show_mode == SYSTEMCTL_SHOW_HELP && argc <= 1)
                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),

src/systemctl/systemctl-util.c

@@ -143,7 +143,7 @@ int get_state_one_unit(sd_bus *bus, const char *unit, UnitActiveState *ret_activ
 
         state = unit_active_state_from_string(buf);
         if (state < 0)
-                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Invalid unit state '%s' for: %s", buf, unit);
+                return log_error_errno(state, "Invalid unit state '%s' for: %s", buf, unit);
 
         *ret_active_state = state;
         return 0;