tipc: fix sparse warnings in new nl api

Fix sparse warnings about non-static declaration of static functions
in the new tipc netlink API.

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index dcf3589..556b26a 100644
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -767,7 +767,8 @@
 	tipc_bclink_unlock();
 }
 
-int __tipc_nl_add_bc_link_stat(struct sk_buff *skb, struct tipc_stats *stats)
+static int __tipc_nl_add_bc_link_stat(struct sk_buff *skb,
+				      struct tipc_stats *stats)
 {
 	int i;
 	struct nlattr *nest;