staging: comedi: das1800: refactor Step 4 of das1800_ai_do_cmdtest()

Refactor this code to reduce the indent level and the > 80 char
lines.

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>

diff --cc drivers/staging/comedi/drivers/das1800.c
Simple merge