[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/include/net/tcp.h b/include/net/tcp.h
index a8af9ae..8b404b1 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -652,8 +652,7 @@
 	/* lower bound for congestion window (optional) */
 	u32 (*min_cwnd)(const struct sock *sk);
 	/* do new cwnd calculation (required) */
-	void (*cong_avoid)(struct sock *sk, u32 ack,
-			   u32 rtt, u32 in_flight, int good_ack);
+	void (*cong_avoid)(struct sock *sk, u32 ack, u32 in_flight, int good_ack);
 	/* call before changing ca_state (optional) */
 	void (*set_state)(struct sock *sk, u8 new_state);
 	/* call when cwnd event occurs (optional) */
@@ -684,8 +683,7 @@
 
 extern struct tcp_congestion_ops tcp_init_congestion_ops;
 extern u32 tcp_reno_ssthresh(struct sock *sk);
-extern void tcp_reno_cong_avoid(struct sock *sk, u32 ack,
-				u32 rtt, u32 in_flight, int flag);
+extern void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 in_flight, int flag);
 extern u32 tcp_reno_min_cwnd(const struct sock *sk);
 extern struct tcp_congestion_ops tcp_reno;