staging: vt6656: rxtx: remove duration_id and void returns.

duration_id is not used by driver anymore so remove the returns
and set all functions in patch to void.

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Link: https://lore.kernel.org/r/04a9c19f-c374-c175-6e46-d1bfbab2f42e@gmail.com


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