[TCP]: Tighten tcp_sock's belt, drop left_out

It is easily calculable when needed and user are not that many
after all.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index ea690af..957e0fb 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1346,8 +1346,6 @@
 		}
 	}
 
-	tp->left_out = tp->sacked_out + tp->lost_out;
-
 	if ((reord < tp->fackets_out) && icsk->icsk_ca_state != TCP_CA_Loss &&
 	    (!tp->frto_highmark || after(tp->snd_una, tp->frto_highmark)))
 		tcp_update_reordering(sk, ((tp->fackets_out + 1) - reord), 0);
@@ -1408,7 +1406,6 @@
 static inline void tcp_reset_reno_sack(struct tcp_sock *tp)
 {
 	tp->sacked_out = 0;
-	tp->left_out = tp->lost_out;
 }
 
 int tcp_use_frto(struct sock *sk)
@@ -1573,7 +1570,6 @@
 
 void tcp_clear_retrans(struct tcp_sock *tp)
 {
-	tp->left_out = 0;
 	tp->retrans_out = 0;
 
 	tp->fackets_out = 0;
@@ -1973,7 +1969,7 @@
 	printk(KERN_DEBUG "Undo %s %u.%u.%u.%u/%u c%u l%u ss%u/%u p%u\n",
 	       msg,
 	       NIPQUAD(inet->daddr), ntohs(inet->dport),
-	       tp->snd_cwnd, tp->left_out,
+	       tp->snd_cwnd, tp->sacked_out + tp->lost_out,
 	       tp->snd_ssthresh, tp->prior_ssthresh,
 	       tp->packets_out);
 }
@@ -2102,7 +2098,6 @@
 
 		DBGUNDO(sk, "partial loss");
 		tp->lost_out = 0;
-		tp->left_out = tp->sacked_out;
 		tcp_undo_cwr(sk, 1);
 		NET_INC_STATS_BH(LINUX_MIB_TCPLOSSUNDO);
 		inet_csk(sk)->icsk_retransmits = 0;
@@ -2126,8 +2121,6 @@
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 
-	tcp_sync_left_out(tp);
-
 	if (tp->retrans_out == 0)
 		tp->retrans_stamp = 0;
 
@@ -2137,7 +2130,7 @@
 	if (inet_csk(sk)->icsk_ca_state != TCP_CA_CWR) {
 		int state = TCP_CA_Open;
 
-		if (tp->left_out || tp->retrans_out || tp->undo_marker)
+		if (tp->sacked_out || tp->retrans_out || tp->undo_marker)
 			state = TCP_CA_Disorder;
 
 		if (inet_csk(sk)->icsk_ca_state != state) {