tcp: make tcp_clear_md5_list static

Trivial. Only used in one file.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 694ea4c..60e2e5d 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1070,7 +1070,7 @@
 }
 EXPORT_SYMBOL(tcp_md5_do_del);
 
-void tcp_clear_md5_list(struct sock *sk)
+static void tcp_clear_md5_list(struct sock *sk)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct tcp_md5sig_key *key;