Currently, the v4l2 control code is a bit silent on errors.
Add debug messages on (hopefully) most of the error paths.
Signed-off-by: NEzequiel Garcia <ezequiel@collabora.com>
Signed-off-by: NHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>