tcp: tcp_init_buffer_space can be static

As of commit 98fa6271
("tcp: refactor setting the initial congestion window") this is called
only from tcp_input.c, so it can be static.
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/tcp.h

@@ -662,7 +662,6 @@ void tcp_initialize_rcv_mss(struct sock *sk);
 int tcp_mtu_to_mss(struct sock *sk, int pmtu);
 int tcp_mss_to_mtu(struct sock *sk, int mss);
 void tcp_mtup_init(struct sock *sk);
-void tcp_init_buffer_space(struct sock *sk);
 
 static inline void tcp_bound_rto(const struct sock *sk)
 {

net/ipv4/tcp_input.c

@@ -437,7 +437,7 @@ static void tcp_grow_window(struct sock *sk, const struct sk_buff *skb)
 /* 3. Try to fixup all. It is made immediately after connection enters
  *    established state.
  */
-void tcp_init_buffer_space(struct sock *sk)
+static void tcp_init_buffer_space(struct sock *sk)
 {
 	int tcp_app_win = sock_net(sk)->ipv4.sysctl_tcp_app_win;
 	struct tcp_sock *tp = tcp_sk(sk);