[media] v4l: Release module if subdev registration fails

If v4l2_device_register_subdev() fails, the reference to the subdev
module taken by the function isn't released. Fix this.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: stable@kernel.org
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/v4l2-device.c

@@ -155,15 +155,18 @@ int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
 	sd->v4l2_dev = v4l2_dev;
 	if (sd->internal_ops && sd->internal_ops->registered) {
 		err = sd->internal_ops->registered(sd);
-		if (err)
+		if (err) {
+			module_put(sd->owner);
 			return err;
 		}
+	}
 
 	/* This just returns 0 if either of the two args is NULL */
 	err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler);
 	if (err) {
 		if (sd->internal_ops && sd->internal_ops->unregistered)
 			sd->internal_ops->unregistered(sd);
+		module_put(sd->owner);
 		return err;
 	}