[TCP]: Don't set SKB owner in tcp_transmit_skb().

The data itself is already charged to the SKB, doing
the skb_set_owner_w() just generates a lot of noise and
extra atomics we don't really need.

Lmbench improvements on lat_tcp are minimal:

before:
TCP latency using localhost: 23.2701 microseconds
TCP latency using localhost: 23.1994 microseconds
TCP latency using localhost: 23.2257 microseconds

after:
TCP latency using localhost: 22.8380 microseconds
TCP latency using localhost: 22.9465 microseconds
TCP latency using localhost: 22.8462 microseconds

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index 5b4f82f..c107d45 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -808,7 +808,7 @@
 			  NIPQUAD(((struct rtable *)skb->dst)->rt_dst));
 
 	SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
-	return ip_queue_xmit(skb, ipfragok);
+	return ip_queue_xmit(skb, skb->sk, ipfragok);
 }
 
 static struct sctp_af sctp_ipv4_specific;