md-cluster: update document for raid10

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c
index d0fd1bd..79bfbc8 100644
--- a/drivers/md/md-cluster.c
+++ b/drivers/md/md-cluster.c
@@ -1478,7 +1478,7 @@ static struct md_cluster_operations cluster_ops = {
 
 static int __init cluster_init(void)
 {
-	pr_warn("md-cluster: EXPERIMENTAL. Use with caution\n");
+	pr_warn("md-cluster: support raid1 and raid10 (limited support)\n");
 	pr_info("Registering Cluster MD functions\n");
 	register_md_cluster_operations(&cluster_ops, THIS_MODULE);
 	return 0;