nvme-core: Use nvme_wq to queue async events and fw activation

async_event_work might race as it is executed from two different
workqueues at the moment.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/nvme/host/core.c

@@ -2676,7 +2676,7 @@ void nvme_complete_async_event(struct nvme_ctrl *ctrl, __le16 status,
 	case NVME_SC_ABORT_REQ:
 		++ctrl->event_limit;
 		if (ctrl->state == NVME_CTRL_LIVE)
-			schedule_work(&ctrl->async_event_work);
+			queue_work(nvme_wq, &ctrl->async_event_work);
 		break;
 	default:
 		break;
@@ -2691,7 +2691,7 @@ void nvme_complete_async_event(struct nvme_ctrl *ctrl, __le16 status,
 		nvme_queue_scan(ctrl);
 		break;
 	case NVME_AER_NOTICE_FW_ACT_STARTING:
-		schedule_work(&ctrl->fw_act_work);
+		queue_work(nvme_wq, &ctrl->fw_act_work);
 		break;
 	default:
 		dev_warn(ctrl->device, "async event result %08x\n", result);