USB: io_ti: fix TIOCGSERIAL

Fix regression introduced by commit f40d78155 ("USB: io_ti: kill custom
closing_wait implementation") which made TIOCGSERIAL return the wrong
value for closing_wait.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Cc: stable <stable@vger.kernel.org> # 3.9
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/serial/io_ti.c

@@ -2357,7 +2357,7 @@ static int get_serial_info(struct edgeport_port *edge_port,
 
 	cwait = edge_port->port->port.closing_wait;
 	if (cwait != ASYNC_CLOSING_WAIT_NONE)
-		cwait = jiffies_to_msecs(closing_wait) / 10;
+		cwait = jiffies_to_msecs(cwait) / 10;
 
 	memset(&tmp, 0, sizeof(tmp));