drm/sched: Use parent fence instead of finished

Using the parent fence instead of the finished fence
to get the job status. This change is to avoid GPU
scheduler timeout error which can cause GPU reset.

Signed-off-by: Arvind Yadav <Arvind.Yadav@amd.com>
Reviewed-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220914164321.2156-6-Arvind.Yadav@amd.com
Signed-off-by: Christian König <christian.koenig@amd.com>