NVMe: Fix hot cpu registration deadlock

The pci-driver calls "get_online_cpus()", which grabs a reference, prior to the device driver's probe. This can deadlock the system if a cpu hot event occurs during the device driver's probe if it registers with cpu hotplug notification using the locked method. Use the lockless version instead to register the cpu notification.

---
 drivers/block/nvme-core.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index cd8a8bc7..fa14deb 100644
@@ -2163,7 +2163,7 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
 	nvme_assign_io_queues(dev);
 
 	dev->nb.notifier_call = &nvme_cpu_notify;
-	result = register_hotcpu_notifier(&dev->nb);
+	result = __register_hotcpu_notifier(&dev->nb);
 	if (result)
 		goto free_queues;
 

1.7.10.4