drivers/gpu/drm: Use kzalloc

Use kzalloc rather than the combination of kmalloc and memset.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression x,size,flags;
statement S;
@@

-x = kmalloc(size,flags);
+x = kzalloc(size,flags);
 if (x == NULL) S
-memset(x, 0, size);
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Reviewed-by: Corbin Simpson <MostAwesomeDude@gmail.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_dma.c b/drivers/gpu/drm/drm_dma.c
index 13f1537..252cbd7 100644
--- a/drivers/gpu/drm/drm_dma.c
+++ b/drivers/gpu/drm/drm_dma.c
@@ -47,12 +47,10 @@
 {
 	int i;
 
-	dev->dma = kmalloc(sizeof(*dev->dma), GFP_KERNEL);
+	dev->dma = kzalloc(sizeof(*dev->dma), GFP_KERNEL);
 	if (!dev->dma)
 		return -ENOMEM;
 
-	memset(dev->dma, 0, sizeof(*dev->dma));
-
 	for (i = 0; i <= DRM_MAX_ORDER; i++)
 		memset(&dev->dma->bufs[i], 0, sizeof(dev->dma->bufs[0]));