[media] media: v4l2-compat-ioctl32: fix missing length copy in put_v4l2_buffer32

In v4l2-compliance utility, test QUERYBUF required correct length
value to go through each planar to check planar's length in
multi-planar buffer type

Signed-off-by: Tiffany Lin <tiffany.lin@mediatek.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: <stable@vger.kernel.org>      # for v3.7 and up
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>