V4L/DVB (9503): v4l: remove inode argument from video_usercopy

The inode argument was never used. Removing it from video_usercopy
brings the function pointer type of video_usercopy in line with similar
v4l2 functions, thus simplifying several drivers.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>