"len" comes from dvb_video_ioctl() and there is a possibility that it is
zero.  We do a divide by len later in the function so that's not ok.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>