staging: vt6656: make pControlURB available life time of driver.

There is no need remove and add the control urb in device open/close.

Move to the probe and disconnect. This make the USB control in/out
functions always available to driver.

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>