l2tp: remove l2tp_tunnel_priv()

This function, and the associated .priv field, are unused.
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/l2tp/l2tp_core.h

@@ -187,8 +187,6 @@ struct l2tp_tunnel {
 						 * was created by userspace */
 
 	struct work_struct	del_work;
-
-	uint8_t			priv[0];	/* private data */
 };
 
 struct l2tp_nl_cmd_ops {
@@ -198,11 +196,6 @@ struct l2tp_nl_cmd_ops {
 	int (*session_delete)(struct l2tp_session *session);
 };
 
-static inline void *l2tp_tunnel_priv(struct l2tp_tunnel *tunnel)
-{
-	return &tunnel->priv[0];
-}
-
 static inline void *l2tp_session_priv(struct l2tp_session *session)
 {
 	return &session->priv[0];