Calling subdevs to handle s_ctrl returned a non-zero return code even if
everything went fine.

Calling STREAMOFF if no STREAMON happened earlier would hit a BUG_ON
in res_free.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>