staging: comedi: daqboard2000: checkpatch.pl cleanup (space before tab)

Fix these checkpatch.pl warnings:

WARNING: please, no space before tabs

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