[media] vb2: change result code of buf_finish to void

The buf_finish op should always work, so change the return type to void.
Update the few drivers that use it.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pawel Osciak <pawel@osciak.com>
Reviewed-by: Pawel Osciak <pawel@osciak.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

diff --cc drivers/media/parport/bw-qcam.c
Simple merge

diff --cc drivers/media/pci/sta2x11/sta2x11_vip.c
Simple merge

diff --cc drivers/media/platform/marvell-ccic/mcam-core.c
Simple merge

diff --cc drivers/media/usb/pwc/pwc-if.c
Simple merge

diff --cc drivers/media/usb/uvc/uvc_queue.c
Simple merge

diff --cc drivers/media/v4l2-core/videobuf2-core.c
Simple merge

diff --cc drivers/staging/media/go7007/go7007-v4l2.c
Simple merge

diff --cc include/media/videobuf2-core.h
Simple merge