tcp: tcp_tx_timestamp() cleanup

tcp_write_queue_tail() call can be factorized.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/tcp.c

@@ -469,8 +469,10 @@ void tcp_init_transfer(struct sock *sk, int bpf_op)
 	tcp_init_buffer_space(sk);
 }
 
-static void tcp_tx_timestamp(struct sock *sk, u16 tsflags, struct sk_buff *skb)
+static void tcp_tx_timestamp(struct sock *sk, u16 tsflags)
 {
+	struct sk_buff *skb = tcp_write_queue_tail(sk);
+
 	if (tsflags && skb) {
 		struct skb_shared_info *shinfo = skb_shinfo(skb);
 		struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
@@ -1041,7 +1043,7 @@ ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset,
 
 out:
 	if (copied) {
-		tcp_tx_timestamp(sk, sk->sk_tsflags, tcp_write_queue_tail(sk));
+		tcp_tx_timestamp(sk, sk->sk_tsflags);
 		if (!(flags & MSG_SENDPAGE_NOTLAST))
 			tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
 	}
@@ -1418,7 +1420,7 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
 
 out:
 	if (copied) {
-		tcp_tx_timestamp(sk, sockc.tsflags, tcp_write_queue_tail(sk));
+		tcp_tx_timestamp(sk, sockc.tsflags);
 		tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
 	}
 out_nopush: