n_hdlc.c: fix check-after-use

The Coverity checker spotted that we'd have already oops'ed if "tty"
was NULL.

Since "tty" can't be NULL when we reach this line of code this patch
removes the NULL check.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/char/n_hdlc.c b/drivers/char/n_hdlc.c
index e8332f3..82bcfb9 100644
--- a/drivers/char/n_hdlc.c
+++ b/drivers/char/n_hdlc.c
@@ -229,7 +229,7 @@
 	wake_up_interruptible (&tty->read_wait);
 	wake_up_interruptible (&tty->write_wait);
 
-	if (tty != NULL && tty->disc_data == n_hdlc)
+	if (tty->disc_data == n_hdlc)
 		tty->disc_data = NULL;	/* Break the tty->n_hdlc link */
 
 	/* Release transmit and receive buffers */