cinterion: failure to set low power in initial EPS setting is fatal

Attempting to change the initial EPS bearer settings while in full
functionality mode shouldn't happen, so make sure we don't attempt to
do that if going into low power mode fails.

plugins/cinterion/mm-broadband-modem-cinterion.c

@@ -1127,15 +1127,16 @@ set_initial_eps_rf_off_ready (MMBaseModem  *self,
                               GAsyncResult *res,
                               GTask        *task)
 {
-    g_autoptr(GError)     error = NULL;
+    GError               *error = NULL;
     SetInitialEpsContext *ctx;
 
     ctx = (SetInitialEpsContext *) g_task_get_task_data (task);
 
     if (!mm_base_modem_at_command_finish (self, res, &error)) {
         mm_obj_warn (self, "couldn't set RF off: %s", error->message);
-        if (!ctx->error)
-            ctx->error = g_steal_pointer (&error);
+        g_task_return_error (task, error);
+        g_object_unref (task);
+        return;
     }
 
     /* Go to next step */