af_key: remove a duplicated skb_orphan()

skb_set_owner_r() will call skb_orphan(), I don't
see any reason to call it twice.

Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

net/key/af_key.c

@@ -203,7 +203,6 @@ static int pfkey_broadcast_one(struct sk_buff *skb, struct sk_buff **skb2,
 	}
 	if (*skb2 != NULL) {
 		if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf) {
-			skb_orphan(*skb2);
 			skb_set_owner_r(*skb2, sk);
 			skb_queue_tail(&sk->sk_receive_queue, *skb2);
 			sk->sk_data_ready(sk, (*skb2)->len);