net: make ndo_get_stats64 a void function

The network device operation for reading statistics is only called
in one place, and it ignores the return value. Having a structure
return value is potentially confusing because some future driver could
incorrectly assume that the return value was used.

Fix all drivers with ndo_get_stats64 to have a void function.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index a479cd9..40f26b6 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -1073,8 +1073,8 @@ static int xennet_change_mtu(struct net_device *dev, int mtu)
 	return 0;
 }
 
-static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev,
-						    struct rtnl_link_stats64 *tot)
+static void xennet_get_stats64(struct net_device *dev,
+			       struct rtnl_link_stats64 *tot)
 {
 	struct netfront_info *np = netdev_priv(dev);
 	int cpu;
@@ -1105,8 +1105,6 @@ static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev,
 
 	tot->rx_errors  = dev->stats.rx_errors;
 	tot->tx_dropped = dev->stats.tx_dropped;
-
-	return tot;
 }
 
 static void xennet_release_tx_bufs(struct netfront_queue *queue)