[IPV6]: Set skb->dev in ip6_pkt_discard_out.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/route.c

@@ -1357,6 +1357,8 @@ int ip6_pkt_discard(struct sk_buff *skb)
 
 int ip6_pkt_discard_out(struct sk_buff **pskb)
 {
+	(*pskb)->dev = (*pskb)->dst->dev;
+	BUG_ON(!(*pskb)->dev);
 	return ip6_pkt_discard(*pskb);
 }