Currently we sync irq to avoid freeing task before using task in I/O
completion. After adding io_uring support, we need to do something similar
for poll queues.  As the process of CQ entries on poll queue are protected
by spinlock cq->lock, we can use spin_lock() + spin_unlock() on cq->lock to
make sure that CQ entries are processed to completion and then the complete
queue is synced.
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Link: https://lore.kernel.org/r/1678169355-76215-4-git-send-email-chenxiang66@hisilicon.comReviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>