em28xx uses core assisted locking, so it shouldn't use .ioctl.
The .ioctl callback was replaced by .unlocked_ioctl for video nodes,
but not for radio nodes. This is now corrected.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>