isdn_tty: TCSBRK{,P} won't reach ->ioctl()

kill the long-dead code - it's been unreachable since 2008.  Redundant, as
well - generic will do exact same thing, since ->break_ctl is NULL here...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

drivers/isdn/i4l/isdn_tty.c

@@ -1412,31 +1412,12 @@ static int
 isdn_tty_ioctl(struct tty_struct *tty, uint cmd, ulong arg)
 {
 	modem_info *info = (modem_info *) tty->driver_data;
-	int retval;
 
 	if (isdn_tty_paranoia_check(info, tty->name, "isdn_tty_ioctl"))
 		return -ENODEV;
 	if (tty_io_error(tty))
 		return -EIO;
 	switch (cmd) {
-	case TCSBRK:   /* SVID version: non-zero arg --> no break */
-#ifdef ISDN_DEBUG_MODEM_IOCTL
-		printk(KERN_DEBUG "ttyI%d ioctl TCSBRK\n", info->line);
-#endif
-		retval = tty_check_change(tty);
-		if (retval)
-			return retval;
-		tty_wait_until_sent(tty, 0);
-		return 0;
-	case TCSBRKP:  /* support for POSIX tcsendbreak() */
-#ifdef ISDN_DEBUG_MODEM_IOCTL
-		printk(KERN_DEBUG "ttyI%d ioctl TCSBRKP\n", info->line);
-#endif
-		retval = tty_check_change(tty);
-		if (retval)
-			return retval;
-		tty_wait_until_sent(tty, 0);
-		return 0;
 	case TIOCSERGETLSR:	/* Get line status register */
 #ifdef ISDN_DEBUG_MODEM_IOCTL
 		printk(KERN_DEBUG "ttyI%d ioctl TIOCSERGETLSR\n", info->line);