IB/rxe: make rxe_release_udp_tunnel static

The function rxe_release_udp_tunnel is only used in rxe_net.c.
So it is necessary to make this function as static.

CC: Srinivas Eeda <srinivas.eeda@oracle.com>
CC: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Zhu Yanjun <yanjun.zhu@oracle.com>
Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/sw/rxe/rxe_net.c

@@ -315,7 +315,7 @@ static struct socket *rxe_setup_udp_tunnel(struct net *net, __be16 port,
 	return sock;
 }
 
-void rxe_release_udp_tunnel(struct socket *sk)
+static void rxe_release_udp_tunnel(struct socket *sk)
 {
 	if (sk)
 		udp_tunnel_sock_release(sk);

drivers/infiniband/sw/rxe/rxe_net.h

@@ -43,8 +43,6 @@ struct rxe_recv_sockets {
 	struct socket *sk6;
 };
 
-void rxe_release_udp_tunnel(struct socket *sk);
-
 struct rxe_dev *rxe_net_add(struct net_device *ndev);
 
 int rxe_net_init(void);