[CIFS] Fix sparse warning

Also update CHANGES file

Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index d3a6b07..1f42f77 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -643,7 +643,7 @@
 	 */
 	if (nd && (nd->flags & LOOKUP_EXCL)) {
 		d_instantiate(direntry, NULL);
-		return 0;
+		return NULL;
 	}
 
 	/* can not grab the rename sem here since it would