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/drivers/ide/ide-probe.c b/drivers/ide/ide-probe.c
index cc58013..5a4c5ea 100644
--- a/drivers/ide/ide-probe.c
+++ b/drivers/ide/ide-probe.c
@@ -1073,14 +1073,14 @@
 		hwgroup->hwif->next = hwif;
 		spin_unlock_irq(&ide_lock);
 	} else {
-		hwgroup = kmalloc_node(sizeof(ide_hwgroup_t), GFP_KERNEL,
+		hwgroup = kmalloc_node(sizeof(ide_hwgroup_t),
+					GFP_KERNEL | __GFP_ZERO,
 					hwif_to_node(hwif->drives[0].hwif));
 		if (!hwgroup)
 	       		goto out_up;
 
 		hwif->hwgroup = hwgroup;
 
-		memset(hwgroup, 0, sizeof(ide_hwgroup_t));
 		hwgroup->hwif     = hwif->next = hwif;
 		hwgroup->rq       = NULL;
 		hwgroup->handler  = NULL;