kobject: fix memory leak in kobject_set_name_vargs

If the call to kvasprintf fails then the old name of the object will be leaked,
this patch fixes the bug by restoring the old name before returning ENOMEM.

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/lib/kobject.c b/lib/kobject.c
index 98b45bb..94b321f 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -265,8 +265,10 @@
 		return 0;
 
 	kobj->name = kvasprintf(GFP_KERNEL, fmt, vargs);
-	if (!kobj->name)
+	if (!kobj->name) {
+		kobj->name = old_name;
 		return -ENOMEM;
+	}
 
 	/* ewww... some of these buggers have '/' in the name ... */
 	while ((s = strchr(kobj->name, '/')))