USB: mos7720: fix hardware flow control

commit a26f009a upstream.

The register access to enable hardware flow control depends on the
device port number and not the port minor number.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/usb/serial/mos7720.c

@@ -1711,7 +1711,7 @@ static void change_port_settings(struct tty_struct *tty,
 		mos7720_port->shadowMCR |= (UART_MCR_XONANY);
 		/* To set hardware flow control to the specified *
 		 * serial port, in SP1/2_CONTROL_REG             */
-		if (port->number)
+		if (port_number)
 			write_mos_reg(serial, dummy, SP_CONTROL_REG, 0x01);
 		else
 			write_mos_reg(serial, dummy, SP_CONTROL_REG, 0x02);