staging: usbip: use kcalloc instead of kzalloc for array allocations

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.
Signed-off-by: Djordje Zekovic <dj@zeko.me>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/usbip/stub_tx.c

@@ -179,7 +179,7 @@ static int stub_send_ret_submit(struct stub_device *sdev)
 		else
 			iovnum = 2;
 
-		iov = kzalloc(iovnum * sizeof(struct kvec), GFP_KERNEL);
+		iov = kcalloc(iovnum, sizeof(struct kvec), GFP_KERNEL);
 
 		if (!iov) {
 			usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_MALLOC);