ipv6: Initial skb->dev and skb->protocol in ip6_output

Move the initialization of skb->dev and skb->protocol from
ip6_finish_output2 to ip6_output. This can make the skb->dev and
skb->protocol information avalaible to the CGROUP eBPF filter.

Signed-off-by: Chenbo Feng <[e-mail]>
Acked-by: Eric Dumazet <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/ipv6/ip6_output.c

···
 	struct in6_addr *nexthop;
 	int ret;
 
-	skb->protocol = htons(ETH_P_IPV6);
-	skb->dev = dev;
-
 	if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) {
 		struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
 
···
 {
 	struct net_device *dev = skb_dst(skb)->dev;
 	struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
+
+	skb->protocol = htons(ETH_P_IPV6);
+	skb->dev = dev;
 
 	if (unlikely(idev->cnf.disable_ipv6)) {
 		IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);