staging: vt6656: use usb_anchor for tx queue.

Use usb_anchor to track tx submitted urbs and initialize the
urb as needed in vnt_tx_context.

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Link: https://lore.kernel.org/r/077f42f8-4f7f-adc4-5a14-955165cef9f1@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>