ip6_tunnel: allow not to count pkts on tstats by passing dev as NULL

[ Upstream commit 6f6a8622 ]

A similar fix to Patch "ip_tunnel: allow not to count pkts on tstats by
setting skb's dev to NULL" is also needed by ip6_tunnel.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

include/net/ip6_tunnel.h

@@ -156,9 +156,12 @@ static inline void ip6tunnel_xmit(struct sock *sk, struct sk_buff *skb,
 	memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
 	pkt_len = skb->len - skb_inner_network_offset(skb);
 	err = ip6_local_out(dev_net(skb_dst(skb)->dev), sk, skb);
+
+	if (dev) {
 		if (unlikely(net_xmit_eval(err)))
 			pkt_len = -1;
 		iptunnel_xmit_stats(dev, pkt_len);
+	}
 }
 #endif
 #endif