l2tp: Fix L2TP_DEBUGFS ifdef tests.

We have to check CONFIG_L2TP_DEBUGFS_MODULE as well as
CONFIG_L2TP_DEBUGFS.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/l2tp/l2tp_eth.c b/net/l2tp/l2tp_eth.c
index 9848faa..ca1164a 100644
--- a/net/l2tp/l2tp_eth.c
+++ b/net/l2tp/l2tp_eth.c
@@ -172,7 +172,7 @@
 	}
 }
 
-#ifdef CONFIG_L2TP_DEBUGFS
+#if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
 static void l2tp_eth_show(struct seq_file *m, void *arg)
 {
 	struct l2tp_session *session = arg;
@@ -244,7 +244,7 @@
 	priv->tunnel_sock = tunnel->sock;
 	session->recv_skb = l2tp_eth_dev_recv;
 	session->session_close = l2tp_eth_delete;
-#ifdef CONFIG_L2TP_DEBUGFS
+#if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
 	session->show = l2tp_eth_show;
 #endif