The rest of V4L files.

There is one list_for_each+list_entry in cpia_pp.c that
wasn't changed because it expects the loop iterator to remain NULL if
the list is empty.

A bug in vivi is fixed; the 'safe' version needs to be used because the loop
deletes the list entries.

Simplify a second loop in vivi and get rid if an un-used variable in that loop.
Signed-off-by: NTrent Piepho <xyzzy@speakeasy.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>