media: media-devnode: fill in media chardev kobject to ease debugging

The media chardev kobject has no name, which made it hard to
debug when kobject debugging is turned on.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/media-devnode.c

@@ -251,6 +251,7 @@ int __must_check media_devnode_register(struct media_device *mdev,
 	/* Part 2: Initialize the character device */
 	cdev_init(&devnode->cdev, &media_devnode_fops);
 	devnode->cdev.owner = owner;
+	kobject_set_name(&devnode->cdev.kobj, "media%d", devnode->minor);
 
 	/* Part 3: Add the media and char device */
 	ret = cdev_device_add(&devnode->cdev, &devnode->dev);