Staging: serqt_usb2: fix qt_close parameters in serqt_usb2

The parameter list for qt_close() was from the old non usb-serial
driver.
Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/serqt_usb2/serqt_usb2.c

@@ -1041,17 +1041,19 @@ static void qt_block_until_empty(struct tty_struct *tty,
 	}
 }
 
-static void qt_close(struct tty_struct *tty, struct usb_serial_port *port,
-		     struct file *filp)
+static void qt_close( struct usb_serial_port *port)
 {
 	struct usb_serial *serial = port->serial;
 	struct quatech_port *qt_port;
 	struct quatech_port *port0;
+	struct tty_struct *tty;
 	int status;
 	unsigned int index;
 	status = 0;
 
 	dbg("%s - port %d\n", __func__, port->number);
+
+	tty = tty_port_tty_get(&port->port);
 	index = tty->index - serial->minor;
 
 	qt_port = qt_get_port_private(port);