tty: Deletion of unnecessary checks before two function calls

The functions put_device() and tty_kref_put() test whether their argument
is NULL and then return immediately.
Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/tty_io.c

@@ -167,7 +167,6 @@ void free_tty_struct(struct tty_struct *tty)
 {
 	if (!tty)
 		return;
-	if (tty->dev)
 	put_device(tty->dev);
 	kfree(tty->write_buf);
 	tty->magic = 0xDEADDEAD;
@@ -1688,7 +1687,6 @@ static void release_tty(struct tty_struct *tty, int idx)
 		tty->link->port->itty = NULL;
 	cancel_work_sync(&tty->port->buf.work);
 
-	if (tty->link)
 	tty_kref_put(tty->link);
 	tty_kref_put(tty);
 }

drivers/tty/tty_port.c

@@ -193,7 +193,6 @@ void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty)
 	unsigned long flags;
 
 	spin_lock_irqsave(&port->lock, flags);
-	if (port->tty)
 	tty_kref_put(port->tty);
 	port->tty = tty_kref_get(tty);
 	spin_unlock_irqrestore(&port->lock, flags);