zink: only set submit_count for fences during flush on unsubmitted batches
What does this MR do and why?
zink: only set submit_count for fences during flush on unsubmitted batches
this otherwise allows re-fencing on a completed batch, which is illegal
fixes #10598
Fixes: aed5e4e1f2b ("zink: Always set mfence->submit_count to the fence submit_count")