diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 5025174..d014ee5 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -515,7 +515,6 @@
 int bdi_setup_and_register(struct backing_dev_info *bdi, char *name,
 			   unsigned int cap)
 {
-	char tmp[32];
 	int err;
 
 	bdi->name = name;
@@ -524,8 +523,8 @@
 	if (err)
 		return err;
 
-	sprintf(tmp, "%.28s%s", name, "-%d");
-	err = bdi_register(bdi, NULL, tmp, atomic_long_inc_return(&bdi_seq));
+	err = bdi_register(bdi, NULL, "%.28s-%ld", name,
+			   atomic_long_inc_return(&bdi_seq));
 	if (err) {
 		bdi_destroy(bdi);
 		return err;