media: rcar-vin: Free buffers with error if hardware stop fails

media: rcar-vin: Free buffers with error if hardware stop fails

The driver already has logic to detect if it fails to stop properly and
report this error to the user. The driver however did not report the
unused buffers or buffers given to the hardware (if any) with an error,
the buffers where instead returned to user-space in the active state.

Build on the existing detection of the error condition and correctly
return the buffers with an error if it triggers.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>