[TCP]: Add tcp_left_out(tp) "back" to get cleaner looking lines

tp->left_out got removed but nothing came to replace it back
then (users just did addition by themselves), so add function
for users now.

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 957e0fb..6bdd053 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1969,7 +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->sacked_out + tp->lost_out,
+	       tp->snd_cwnd, tcp_left_out(tp),
 	       tp->snd_ssthresh, tp->prior_ssthresh,
 	       tp->packets_out);
 }