nouveau: be more careful about freeing temporary transfer buffers

Deleting a buffer does not flush the command stream. Make sure that we
wait for the copies to finish before deleting the temporary bo.

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Cc: mesa-stable@lists.freedesktop.org
Tested-by: Marcin Ĺšlusarz <marcin.slusarz@gmail.com>
5 files changed