media: vicodec: move v4l2_ctrl_request_complete after spin_unlock

v4l2_ctrl_request_complete can sleep, so can't be called while
a spinlock is held.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>