hv_netvsc: use kcalloc

BugLink: http://bugs.launchpad.net/bugs/1650059

Better to use kcalloc rather than kzalloc and multiply for an array.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit e53a9c2a)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/net/hyperv/netvsc.c

@@ -421,8 +421,8 @@ static int netvsc_init_buf(struct hv_device *device)
 	net_device->map_words = DIV_ROUND_UP(net_device->send_section_cnt,
 					     BITS_PER_LONG);
 
-	net_device->send_section_map =
-		kzalloc(net_device->map_words * sizeof(ulong), GFP_KERNEL);
+	net_device->send_section_map = kcalloc(net_device->map_words,
+					       sizeof(ulong), GFP_KERNEL);
 	if (net_device->send_section_map == NULL) {
 		ret = -ENOMEM;
 		goto cleanup;