TTY: Fix error return from tty_ldisc_open()

The backported version of "TTY: ldisc, fix open flag handling" in
2.6.32.27 causes tty_ldisc_open() to return 0 on error.  Fix that.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/char/tty_ldisc.c

@@ -451,6 +451,7 @@ static int tty_ldisc_open(struct tty_struct *tty, struct tty_ldisc *ld)
 		ret = ld->ops->open(tty);
 		if (ret)
 			clear_bit(TTY_LDISC_OPEN, &tty->flags);
+		return ret;
 	}
 	return 0;
 }