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/node.c b/net/tipc/node.c
index 72a75d4..82e5edd 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -609,7 +609,7 @@
 }
 
 /* Caller should hold node lock for the passed node */
-int __tipc_nl_add_node(struct tipc_nl_msg *msg, struct tipc_node *node)
+static int __tipc_nl_add_node(struct tipc_nl_msg *msg, struct tipc_node *node)
 {
 	void *hdr;
 	struct nlattr *attrs;