[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_bic.c b/net/ipv4/tcp_bic.c
index dd9ef65..519de09 100644
--- a/net/ipv4/tcp_bic.c
+++ b/net/ipv4/tcp_bic.c
@@ -137,7 +137,7 @@
 }
 
 static void bictcp_cong_avoid(struct sock *sk, u32 ack,
-			      u32 seq_rtt, u32 in_flight, int data_acked)
+			      u32 in_flight, int data_acked)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct bictcp *ca = inet_csk_ca(sk);