staging: comedi: ni_daq_700: fix some trailing whitespace errors

checkpatch.pl reports 2 errors about trailing whitespace in this file.
Fix them.

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>