staging: vt6656: rxtx remove unused need_ack

need_ack is no longer used by driver remove it.

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Link: https://lore.kernel.org/r/f19dfbde-23a6-ba79-d988-576d2e3bcf62@gmail.com


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