staging: comedi: vmk80xx: tidy up vmk80xx_cnt_insn_config()

Tidy up this (*insn_config) function to follow the normal format in
comedi drivers.

INSN_CONFIG_RESET instructions do not have any extra parameters (insn->n is
always 1) so the for loop used to write the packet doesn't make any sense.
Remove it and just write the single packet.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>