Slab allocators: Replace explicit zeroing with __GFP_ZERO

kmalloc_node() and kmem_cache_alloc_node() were not available in a zeroing
variant in the past.  But with __GFP_ZERO it is possible now to do zeroing
while allocating.

Use __GFP_ZERO to remove the explicit clearing of memory via memset whereever
we can.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/block/elevator.c b/block/elevator.c
index 4769a25..d265963 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -177,11 +177,10 @@
 	elevator_t *eq;
 	int i;
 
-	eq = kmalloc_node(sizeof(elevator_t), GFP_KERNEL, q->node);
+	eq = kmalloc_node(sizeof(elevator_t), GFP_KERNEL | __GFP_ZERO, q->node);
 	if (unlikely(!eq))
 		goto err;
 
-	memset(eq, 0, sizeof(*eq));
 	eq->ops = &e->ops;
 	eq->elevator_type = e;
 	kobject_init(&eq->kobj);