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-zoltrix.c b/drivers/media/radio/radio-zoltrix.c
index 4d76e71..0d43e84 100644
--- a/drivers/media/radio/radio-zoltrix.c
+++ b/drivers/media/radio/radio-zoltrix.c
@@ -439,6 +439,7 @@
 	.name		= "Zoltrix Radio Plus",
 	.fops           = &zoltrix_fops,
 	.ioctl_ops 	= &zoltrix_ioctl_ops,
+	.release	= video_device_release_empty,
 };
 
 static int __init zoltrix_init(void)