Phonet: fix /proc/net/phonet with network namespaces

seq_open_net() and seq_release() are needed for seq_file_net().

Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/phonet/socket.c b/net/phonet/socket.c
index aa1617a..5f26c37 100644
--- a/net/phonet/socket.c
+++ b/net/phonet/socket.c
@@ -498,7 +498,8 @@
 
 static int pn_sock_open(struct inode *inode, struct file *file)
 {
-	return seq_open(file, &pn_sock_seq_ops);
+	return seq_open_net(inode, file, &pn_sock_seq_ops,
+				sizeof(struct seq_net_private));
 }
 
 const struct file_operations pn_sock_seq_fops = {
@@ -506,5 +507,5 @@
 	.open = pn_sock_open,
 	.read = seq_read,
 	.llseek = seq_lseek,
-	.release = seq_release,
+	.release = seq_release_net,
 };