USB: ftdi_sio: remove obsolete check in unthrottle

No need to check ASYNCB_INITIALIZED anymore as commit
e1108a63 (usb_serial: Use the shutdown()
operation) make sure that there is no longer any call to unthrottle
after device specific close (in which the read urb is killed).
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/serial/ftdi_sio.c

@@ -2492,8 +2492,7 @@ void ftdi_unthrottle(struct tty_struct *tty)
 	port->throttled = port->throttle_req = 0;
 	spin_unlock_irqrestore(&port->lock, flags);
 
-	/* Resubmit urb if throttled and open. */
-	if (was_throttled && test_bit(ASYNCB_INITIALIZED, &port->port.flags))
+	if (was_throttled)
 		ftdi_submit_read_urb(port, GFP_KERNEL);
 }