media: rkisp1: stats: Simplify (un)registration

Simplify error handling at registration time as media_entity_cleanup()
can be called on an uninitialized entity, and make
rkisp1_stats_unregister() safe to be called on an unregistered stats
node to prepare for simplification of error handling at probe time.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Ricardo Ribalda <ribalda@chromium.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

drivers/media/platform/rockchip/rkisp1/rkisp1-stats.c

@@ -463,21 +463,21 @@ int rkisp1_stats_register(struct rkisp1_device *rkisp1)
 	node->pad.flags = MEDIA_PAD_FL_SINK;
 	ret = media_entity_pads_init(&vdev->entity, 1, &node->pad);
 	if (ret)
-		goto err_mutex_destroy;
+		goto error;
 
 	ret = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
 	if (ret) {
 		dev_err(&vdev->dev,
 			"failed to register %s, ret=%d\n", vdev->name, ret);
-		goto err_cleanup_media_entity;
+		goto error;
 	}
 
 	return 0;
 
-err_cleanup_media_entity:
+error:
 	media_entity_cleanup(&vdev->entity);
-err_mutex_destroy:
 	mutex_destroy(&node->vlock);
+	stats->rkisp1 = NULL;
 	return ret;
 }
 
@@ -487,6 +487,9 @@ void rkisp1_stats_unregister(struct rkisp1_device *rkisp1)
 	struct rkisp1_vdev_node *node = &stats->vnode;
 	struct video_device *vdev = &node->vdev;
 
+	if (!stats->rkisp1)
+		return;
+
 	vb2_video_unregister_device(vdev);
 	media_entity_cleanup(&vdev->entity);
 	mutex_destroy(&node->vlock);