[TCP]: remove unused argument to cong_avoid op

None of the existing TCP congestion controls use the rtt value pased
in the ca_ops->cong_avoid interface.  Which is lucky because seq_rtt
could have been -1 when handling a duplicate ack.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_vegas.c b/net/ipv4/tcp_vegas.c
index e218a51..914e030 100644
--- a/net/ipv4/tcp_vegas.c
+++ b/net/ipv4/tcp_vegas.c
@@ -163,13 +163,13 @@
 EXPORT_SYMBOL_GPL(tcp_vegas_cwnd_event);
 
 static void tcp_vegas_cong_avoid(struct sock *sk, u32 ack,
-				 u32 seq_rtt, u32 in_flight, int flag)
+				 u32 in_flight, int flag)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct vegas *vegas = inet_csk_ca(sk);
 
 	if (!vegas->doing_vegas_now)
-		return tcp_reno_cong_avoid(sk, ack, seq_rtt, in_flight, flag);
+		return tcp_reno_cong_avoid(sk, ack, in_flight, flag);
 
 	/* The key players are v_beg_snd_una and v_beg_snd_nxt.
 	 *
@@ -228,7 +228,7 @@
 			/* We don't have enough RTT samples to do the Vegas
 			 * calculation, so we'll behave like Reno.
 			 */
-			tcp_reno_cong_avoid(sk, ack, seq_rtt, in_flight, flag);
+			tcp_reno_cong_avoid(sk, ack, in_flight, flag);
 		} else {
 			u32 rtt, target_cwnd, diff;