[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_yeah.c b/net/ipv4/tcp_yeah.c
index 545ed23..c04b7c6 100644
--- a/net/ipv4/tcp_yeah.c
+++ b/net/ipv4/tcp_yeah.c
@@ -70,7 +70,7 @@
 }
 
 static void tcp_yeah_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 yeah *yeah = inet_csk_ca(sk);