Staging: comedi: Fix WARNING issue in dt2801.c

This is a patch to the dt2801.c file that fixes up a Block comments
issues found by the checkpatch.pl tool.

i.e. Block comments use a trailing */ on a separate line

Signed-off-by: Ravishankar Karkala Mallikarjunayya <ravishankarkm32@gmail.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>