ip6_tunnel: use dev_sw_netstats_rx_add()

We have a convenient helper, let's use it.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/ipv6/ip6_tunnel.c

@@ -796,7 +796,6 @@ static int __ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
 						struct sk_buff *skb),
 			 bool log_ecn_err)
 {
-	struct pcpu_sw_netstats *tstats;
 	const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 	int err;
 
@@ -856,11 +855,7 @@ static int __ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
 		}
 	}
 
-	tstats = this_cpu_ptr(tunnel->dev->tstats);
-	u64_stats_update_begin(&tstats->syncp);
-	tstats->rx_packets++;
-	tstats->rx_bytes += skb->len;
-	u64_stats_update_end(&tstats->syncp);
+	dev_sw_netstats_rx_add(tunnel->dev, skb->len);
 
 	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev)));