Staging: comedi: addi-data: clean-up variable use in hwdrv_apci035.c

The variable ui_Command is as of right now being cleared to a
value of zero between everytime that it writes to a port and then takes a
new value from a port.  Seems like this zeroing is unnecessary, so we can
just remove these lines.

Signed-off-by: Chase Southwood <chase.southwood@yahoo.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>