pty: fix O_CLOEXEC for TIOCGPTPEER

It was being ignored because the flags were not passed to fd allocation.

Fixes: 54ebbfb16034 ("tty: add TIOCGPTPEER ioctl")
Signed-off-by: Matthijs van Duin <matthijsvanduin@gmail.com>
Acked-by: Aleksa Sarai <asarai@suse.de>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/pty.c

@@ -625,7 +625,7 @@ int ptm_open_peer(struct file *master, struct tty_struct *tty, int flags)
 	if (tty->driver != ptm_driver)
 		return -EIO;
 
-	fd = get_unused_fd_flags(0);
+	fd = get_unused_fd_flags(flags);
 	if (fd < 0) {
 		retval = fd;
 		goto err;