[media] v4l: vsp1: Use the new media graph walk interface

The media graph walk requires initialisation and cleanup soon. Update the
users to perform the soon necessary API calls.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/platform/vsp1/vsp1_video.c

@@ -386,6 +386,12 @@ static int vsp1_pipeline_validate(struct vsp1_pipeline *pipe,
 	mutex_lock(&mdev->graph_mutex);
 
 	/* Walk the graph to locate the entities and video nodes. */
+	ret = media_entity_graph_walk_init(&graph, mdev);
+	if (ret) {
+		mutex_unlock(&mdev->graph_mutex);
+		return ret;
+	}
+
 	media_entity_graph_walk_start(&graph, entity);
 
 	while ((entity = media_entity_graph_walk_next(&graph))) {
@@ -419,6 +425,8 @@ static int vsp1_pipeline_validate(struct vsp1_pipeline *pipe,
 
 	mutex_unlock(&mdev->graph_mutex);
 
+	media_entity_graph_walk_cleanup(&graph);
+
 	/* We need one output and at least one input. */
 	if (pipe->num_inputs == 0 || !pipe->output) {
 		ret = -EPIPE;