media: rcar-vin: unregister video device on driver removal

If the video device was registered by the complete() callback it should
be unregistered when a device is unbound from the driver. Protect from
printing an uninitialized video device node name by adding a check in
rvin_v4l2_unregister() to identify that the video device is registered.
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/platform/rcar-vin/rcar-core.c

@@ -272,6 +272,8 @@ static int rcar_vin_remove(struct platform_device *pdev)
 
 	pm_runtime_disable(&pdev->dev);
 
+	rvin_v4l2_unregister(vin);
+
 	v4l2_async_notifier_unregister(&vin->notifier);
 	v4l2_async_notifier_cleanup(&vin->notifier);
 

drivers/media/platform/rcar-vin/rcar-v4l2.c

@@ -841,6 +841,9 @@ static const struct v4l2_file_operations rvin_fops = {
 
 void rvin_v4l2_unregister(struct rvin_dev *vin)
 {
+	if (!video_is_registered(&vin->vdev))
+		return;
+
 	v4l2_info(&vin->v4l2_dev, "Removing %s\n",
 		  video_device_node_name(&vin->vdev));