[media] v4l2-ctrls: Use kcalloc instead of kzalloc to allocate array

The advantage of kcalloc is, that will prevent integer overflows which could
result from the multiplication of number of elements and size and it is also
a bit nicer to read.

The semantic patch that makes this change is available
in https://lkml.org/lkml/2011/11/25/107

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/stk-webcam.c

@@ -377,8 +377,8 @@ static int stk_prepare_iso(struct stk_camera *dev)
 	if (dev->isobufs)
 		STK_ERROR("isobufs already allocated. Bad\n");
 	else
-		dev->isobufs = kzalloc(MAX_ISO_BUFS * sizeof(*dev->isobufs),
-					GFP_KERNEL);
+		dev->isobufs = kcalloc(MAX_ISO_BUFS, sizeof(*dev->isobufs),
+				       GFP_KERNEL);
 	if (dev->isobufs == NULL) {
 		STK_ERROR("Unable to allocate iso buffers\n");
 		return -ENOMEM;

drivers/media/video/v4l2-ctrls.c

@@ -1109,8 +1109,8 @@ int v4l2_ctrl_handler_init(struct v4l2_ctrl_handler *hdl,
 	INIT_LIST_HEAD(&hdl->ctrls);
 	INIT_LIST_HEAD(&hdl->ctrl_refs);
 	hdl->nr_of_buckets = 1 + nr_of_controls_hint / 8;
-	hdl->buckets = kzalloc(sizeof(hdl->buckets[0]) * hdl->nr_of_buckets,
-								GFP_KERNEL);
+	hdl->buckets = kcalloc(hdl->nr_of_buckets, sizeof(hdl->buckets[0]),
+			       GFP_KERNEL);
 	hdl->error = hdl->buckets ? 0 : -ENOMEM;
 	return hdl->error;
 }