[TCP] mtu probing: move tcp-specific data out of inet_connection_sock

This moves some TCP-specific MTU probing state out of
inet_connection_sock back to tcp_sock.

Signed-off-by: John Heffner <jheffner@psc.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 8197b5e..518e568 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1238,8 +1238,8 @@
 		update_send_head(sk, tp, nskb);
 
 		icsk->icsk_mtup.probe_size = tcp_mss_to_mtu(sk, nskb->len);
-		icsk->icsk_mtup.probe_seq_start = TCP_SKB_CB(nskb)->seq;
-		icsk->icsk_mtup.probe_seq_end = TCP_SKB_CB(nskb)->end_seq;
+		tp->mtu_probe.probe_seq_start = TCP_SKB_CB(nskb)->seq;
+		tp->mtu_probe.probe_seq_end = TCP_SKB_CB(nskb)->end_seq;
 
 		return 1;
 	}