[TCP]: Restore SKB socket owner setting in tcp_transmit_skb().

Revert 931731123a103cfb3f70ac4b7abfc71d94ba1f03

We can't elide the skb_set_owner_w() here because things like certain
netfilter targets (such as owner MATCH) need a socket to be set on the
SKB for correct operation.

Thanks to Jan Engelhardt and other netfilter list members for
pointing this out.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 23e32c8..975f447 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -467,6 +467,7 @@
 
 	th = (struct tcphdr *) skb_push(skb, tcp_header_size);
 	skb->h.th = th;
+	skb_set_owner_w(skb, sk);
 
 	/* Build TCP header and checksum it. */
 	th->source		= inet->sport;
@@ -540,7 +541,7 @@
 	if (after(tcb->end_seq, tp->snd_nxt) || tcb->seq == tcb->end_seq)
 		TCP_INC_STATS(TCP_MIB_OUTSEGS);
 
-	err = icsk->icsk_af_ops->queue_xmit(skb, sk, 0);
+	err = icsk->icsk_af_ops->queue_xmit(skb, 0);
 	if (likely(err <= 0))
 		return err;