ipv4/ipv6: switch to dev_get_tstats64

Replace ip_tunnel_get_stats64() with the new identical core function
dev_get_tstats64().

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 5e2c34c..4dc5f93 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -1396,7 +1396,7 @@ static const struct net_device_ops ipip6_netdev_ops = {
 	.ndo_uninit	= ipip6_tunnel_uninit,
 	.ndo_start_xmit	= sit_tunnel_xmit,
 	.ndo_do_ioctl	= ipip6_tunnel_ioctl,
-	.ndo_get_stats64 = ip_tunnel_get_stats64,
+	.ndo_get_stats64 = dev_get_tstats64,
 	.ndo_get_iflink = ip_tunnel_get_iflink,
 	.ndo_tunnel_ctl = ipip6_tunnel_ctl,
 };