V4L/DVB (8783): v4l: add all missing video_device release callbacks

All drivers that call video_device_register where checked to see if they
set the release callback of struct video_device. Where that callback was
missing it was added.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/radio/radio-cadet.c b/drivers/media/radio/radio-cadet.c
index 04c3698..0490a1f 100644
--- a/drivers/media/radio/radio-cadet.c
+++ b/drivers/media/radio/radio-cadet.c
@@ -589,6 +589,7 @@
 	.name		= "Cadet radio",
 	.fops           = &cadet_fops,
 	.ioctl_ops 	= &cadet_ioctl_ops,
+	.release	= video_device_release_empty,
 };
 
 #ifdef CONFIG_PNP