V4L/DVB (6266): videobuf cleanup: mmap check is common to all videobuf. Make it at core

Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
http://thread.gmane.org/gmane.comp.video.video4linux/34978/focus=34981
Reviewed-by: Ricardo Cerqueira <v4l@cerqueira.org>
6 files changed