tcp: make proc_tcp_fastopen_key static

Detected by sparse.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/sysctl_net_ipv4.c

@@ -232,7 +232,7 @@ static int ipv4_tcp_mem(ctl_table *ctl, int write,
 	return 0;
 }
 
-int proc_tcp_fastopen_key(ctl_table *ctl, int write, void __user *buffer,
+static int proc_tcp_fastopen_key(ctl_table *ctl, int write, void __user *buffer,
 				 size_t *lenp, loff_t *ppos)
 {
 	ctl_table tbl = { .maxlen = (TCP_FASTOPEN_KEY_LENGTH * 2 + 10) };