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/deadline-iosched.c b/block/deadline-iosched.c
index 6d673e9..87ca02a 100644
--- a/block/deadline-iosched.c
+++ b/block/deadline-iosched.c
@@ -360,10 +360,9 @@
 {
 	struct deadline_data *dd;
 
-	dd = kmalloc_node(sizeof(*dd), GFP_KERNEL, q->node);
+	dd = kmalloc_node(sizeof(*dd), GFP_KERNEL | __GFP_ZERO, q->node);
 	if (!dd)
 		return NULL;
-	memset(dd, 0, sizeof(*dd));
 
 	INIT_LIST_HEAD(&dd->fifo_list[READ]);
 	INIT_LIST_HEAD(&dd->fifo_list[WRITE]);