datapath: make ndo_get_stats64 a void function

Upstream commit:

    commit bc1f44709cf27fb2a5766cadafe7e2ad5e9cb221
    Author: stephen hemminger <stephen@networkplumber.org>
    Date:   Fri Jan 6 19:12:52 2017 -0800

    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>

This seems to be fine for all prior Linux versions as well.

Signed-off-by: Jarno Rajahalme <jarno@ovn.org>

datapath/vport-internal_dev.c

@@ -106,7 +106,7 @@ static void internal_dev_destructor(struct net_device *dev)
 	free_netdev(dev);
 }
 
-static struct rtnl_link_stats64 *
+static void
 internal_get_stats(struct net_device *dev, struct rtnl_link_stats64 *stats)
 {
 	int i;
@@ -134,8 +134,6 @@ internal_get_stats(struct net_device *dev, struct rtnl_link_stats64 *stats)
 		stats->tx_bytes         += local_stats.tx_bytes;
 		stats->tx_packets       += local_stats.tx_packets;
 	}
-
-	return stats;
 }
 
 #ifdef HAVE_IFF_PHONY_HEADROOM
@@ -151,7 +149,7 @@ static const struct net_device_ops internal_dev_netdev_ops = {
 	.ndo_start_xmit = internal_dev_xmit,
 	.ndo_set_mac_address = eth_mac_addr,
 	.ndo_change_mtu = internal_dev_change_mtu,
-	.ndo_get_stats64 = internal_get_stats,
+	.ndo_get_stats64 = (void *)internal_get_stats,
 #ifdef HAVE_IFF_PHONY_HEADROOM
 #ifndef HAVE_NET_DEVICE_OPS_WITH_EXTENDED
 	.ndo_set_rx_headroom = internal_set_rx_headroom,