[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/char/n_hdlc.c b/drivers/char/n_hdlc.c
index b3dbff1..5079beda 100644
--- a/drivers/char/n_hdlc.c
+++ b/drivers/char/n_hdlc.c
@@ -960,7 +960,7 @@
 static void __exit n_hdlc_exit(void)
 {
 	/* Release tty registration of line discipline */
-	int status = tty_register_ldisc(N_HDLC, NULL);
+	int status = tty_unregister_ldisc(N_HDLC);
 
 	if (status)
 		printk(hdlc_unregister_fail, status);