8250: fix set_ldisc operation

The ldisc number now gets passed into ->set_ldisc.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/serial/8250.c

@@ -2404,14 +2404,9 @@ serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
 }
 
 static void
-serial8250_set_ldisc(struct uart_port *port)
+serial8250_set_ldisc(struct uart_port *port, int new)
 {
-	int line = port->line;
-
-	if (line >= port->state->port.tty->driver->num)
-		return;
-
-	if (port->state->port.tty->ldisc->ops->num == N_PPS) {
+	if (new == N_PPS) {
 		port->flags |= UPF_HARDPPS_CD;
 		serial8250_enable_ms(port);
 	} else