nvme-core: use list_add_tail_rcu instead of list_add_tail for nvme_init_ns_head

The "list" of nvme_ns_head is used as rcu list, now in nvme_init_ns_head
list_add_tail is used to add ns->siblings to the rcu list. It is not safe.
Should use list_add_tail_rcu instead of list_add_tail.
Signed-off-by: Chao Leng <lengchao@huawei.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/host/core.c

@@ -3829,7 +3829,7 @@ static int nvme_init_ns_head(struct nvme_ns *ns, unsigned nsid,
 		}
 	}
 
-	list_add_tail(&ns->siblings, &head->list);
+	list_add_tail_rcu(&ns->siblings, &head->list);
 	ns->head = head;
 	mutex_unlock(&ctrl->subsys->lock);
 	return 0;