TTY: simplify tty_driver_lookup_tty a bit

Remove the useless local variable and return the value itself.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/tty_io.c

@@ -1230,13 +1230,10 @@ static void tty_line_name(struct tty_driver *driver, int index, char *p)
 static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver,
 		struct inode *inode, int idx)
 {
-	struct tty_struct *tty;
-
 	if (driver->ops->lookup)
 		return driver->ops->lookup(driver, inode, idx);
 
-	tty = driver->ttys[idx];
-	return tty;
+	return driver->ttys[idx];
 }
 
 /**