tcp: Remove redundant code entering quickack mode

tcp_enter_quickack_mode() already calls tcp_incr_quickack() and sets
icsk->icsk_ack.ato  to TCP_ATO_MIN. This patch removes the duplication.
Signed-off-by: Vijay Subramanian <subramanian.vijay@gmail.com>
Reviewed-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/tcp_input.c

@@ -5734,8 +5734,6 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
 			 */
 			inet_csk_schedule_ack(sk);
 			icsk->icsk_ack.lrcvtime = tcp_time_stamp;
-			icsk->icsk_ack.ato	 = TCP_ATO_MIN;
-			tcp_incr_quickack(sk);
 			tcp_enter_quickack_mode(sk);
 			inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
 						  TCP_DELACK_MAX, TCP_RTO_MAX);