[PATCH] Convert users to tty_unregister_ldisc()

tty_register_ldisc(N_FOO, NULL) => tty_unregister_ldisc(N_FOO)

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/net/wan/x25_asy.c b/drivers/net/wan/x25_asy.c
index 1c540d8..bdf672c 100644
--- a/drivers/net/wan/x25_asy.c
+++ b/drivers/net/wan/x25_asy.c
@@ -829,7 +829,7 @@
 	}
 
 	kfree(x25_asy_devs);
-	tty_register_ldisc(N_X25, NULL);
+	tty_unregister_ldisc(N_X25);
 }
 
 module_init(init_x25_asy);