[TCP]: Fix TSO deferring

I'd say that most of what tcp_tso_should_defer had in between
there was dead code because of this.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/tcp_output.c

@@ -1230,7 +1230,8 @@ static int tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb)
 		goto send_now;
 
 	/* Defer for less than two clock ticks. */
-	if (!tp->tso_deferred && ((jiffies<<1)>>1) - (tp->tso_deferred>>1) > 1)
+	if (tp->tso_deferred &&
+	    ((jiffies << 1) >> 1) - (tp->tso_deferred >> 1) > 1)
 		goto send_now;
 
 	in_flight = tcp_packets_in_flight(tp);