media: davinci: vpif_capture: fix potential double free

In case of errors vpif_probe_complete() releases memory for vpif_obj.sd
and unregisters the V4L2 device. But then this is done again by
vpif_probe() itself. The patch removes the cleaning from
vpif_probe_complete().

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Evgeny Novikov <novikov@ispras.ru>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>