[TCP]: Make tcp_match_skb_to_sack() static.

tcp_match_skb_to_sack() can become static.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/tcp_input.c

@@ -1204,7 +1204,7 @@ static int tcp_check_dsack(struct tcp_sock *tp, struct sk_buff *ack_skb,
  * which may fail and creates some hassle (caller must handle error case
  * returns).
  */
-int tcp_match_skb_to_sack(struct sock *sk, struct sk_buff *skb,
+static int tcp_match_skb_to_sack(struct sock *sk, struct sk_buff *skb,
 				 u32 start_seq, u32 end_seq)
 {
 	int in_sack, err;