tipc: call tsk_set_importance from tipc_topsrv_create_listener

Avoid using kernel_setsockopt for the TIPC_IMPORTANCE option when we can
just use the internal helper.  The only change needed is to pass a struct
sock instead of tipc_sock, which is private to socket.c

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/tipc/socket.h b/net/tipc/socket.h
index 235b967..b11575a 100644
--- a/net/tipc/socket.h
+++ b/net/tipc/socket.h
@@ -75,4 +75,6 @@ u32 tipc_sock_get_portid(struct sock *sk);
 bool tipc_sk_overlimit1(struct sock *sk, struct sk_buff *skb);
 bool tipc_sk_overlimit2(struct sock *sk, struct sk_buff *skb);
 
+int tsk_set_importance(struct sock *sk, int imp);
+
 #endif