switch debugfs to umode_t

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 2b8ba3a..99930ec 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1408,7 +1408,7 @@
 
 static int __init fail_page_alloc_debugfs(void)
 {
-	mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
+	umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
 	struct dentry *dir;
 
 	dir = fault_create_debugfs_attr("fail_page_alloc", NULL,