nvme_poll_queues is already protected by q->lock, and
AIO callbacks are invoked outside the AioContext lock.
So remove the acquire/release pair in nvme_handle_event.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20180814062739.19640-1-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>