ceph: cleanup ACCESS_ONCE -> READ_ONCE

This removes the uses of ACCESS_ONCE in favor of READ_ONCE

Signed-off-by: Seraphime Kirkovski <kirkseraph@gmail.com>
Signed-off-by: Yan, Zheng <zyan@redhat.com>
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 8ab1fdf..d438556 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -1194,7 +1194,7 @@ static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
 	struct inode *dir;
 
 	if (flags & LOOKUP_RCU) {
-		parent = ACCESS_ONCE(dentry->d_parent);
+		parent = READ_ONCE(dentry->d_parent);
 		dir = d_inode_rcu(parent);
 		if (!dir)
 			return -ECHILD;