mm/slub: close possible memory-leak in kmem_cache_alloc_bulk()

Under certain circumstances we could leak elements which were moved to
the local "to_free" list. The damage is limited since I can't find
any users here.

Cc: stable-rt@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
diff --git a/mm/slub.c b/mm/slub.c
index b183c52..b3626ab 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3026,6 +3026,7 @@
 	return i;
 error:
 	local_irq_enable();
+	free_delayed(&to_free);
 	slab_post_alloc_hook(s, flags, i, p);
 	__kmem_cache_free_bulk(s, i, p);
 	return 0;