nvme: cleanup double shift issue

The problem here is that set_bit() and test_bit() take a bit number so
we should be passing 0 but instead we're passing (1 << 0) which leads to
a double shift.  It doesn't cause a runtime bug in the current code
because it's done consistently and we only set that one bit.

I decided to just re-use NVME_AER_NOTICE_NS_CHANGED instead of
introducing a new define for this.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-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

@@ -3245,7 +3245,7 @@ static void nvme_scan_work(struct work_struct *work)
 
 	WARN_ON_ONCE(!ctrl->tagset);
 
-	if (test_and_clear_bit(EVENT_NS_CHANGED, &ctrl->events)) {
+	if (test_and_clear_bit(NVME_AER_NOTICE_NS_CHANGED, &ctrl->events)) {
 		if (nvme_scan_changed_ns_log(ctrl))
 			goto out_sort_namespaces;
 		dev_info(ctrl->device, "rescanning namespaces.\n");
@@ -3386,7 +3386,7 @@ static void nvme_handle_aen_notice(struct nvme_ctrl *ctrl, u32 result)
 {
 	switch ((result & 0xff00) >> 8) {
 	case NVME_AER_NOTICE_NS_CHANGED:
-		set_bit(EVENT_NS_CHANGED, &ctrl->events);
+		set_bit(NVME_AER_NOTICE_NS_CHANGED, &ctrl->events);
 		nvme_queue_scan(ctrl);
 		break;
 	case NVME_AER_NOTICE_FW_ACT_STARTING:

drivers/nvme/host/nvme.h

@@ -194,7 +194,6 @@ struct nvme_ctrl {
 	struct delayed_work ka_work;
 	struct nvme_command ka_cmd;
 	struct work_struct fw_act_work;
-#define EVENT_NS_CHANGED		(1 << 0)
 	unsigned long events;
 
 	/* Power saving configuration */