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/ipvlan/ipvlan_main.c b/drivers/net/ipvlan/ipvlan_main.c
index ce7ca6a..1cdb8c5 100644
--- a/drivers/net/ipvlan/ipvlan_main.c
+++ b/drivers/net/ipvlan/ipvlan_main.c
@@ -303,8 +303,8 @@ static void ipvlan_set_multicast_mac_filter(struct net_device *dev)
 	dev_mc_sync(ipvlan->phy_dev, dev);
 }
 
-static struct rtnl_link_stats64 *ipvlan_get_stats64(struct net_device *dev,
-						    struct rtnl_link_stats64 *s)
+static void ipvlan_get_stats64(struct net_device *dev,
+			       struct rtnl_link_stats64 *s)
 {
 	struct ipvl_dev *ipvlan = netdev_priv(dev);
 
@@ -341,7 +341,6 @@ static struct rtnl_link_stats64 *ipvlan_get_stats64(struct net_device *dev,
 		s->rx_dropped = rx_errs;
 		s->tx_dropped = tx_drps;
 	}
-	return s;
 }
 
 static int ipvlan_vlan_rx_add_vid(struct net_device *dev, __be16 proto, u16 vid)