Staging: comedi: drivers: skel: Add whitespace to example comment block

The Comedi team have a script 'dump_doc' to extract text from the driver
comment block (starting with line 'Driver:') in (most of) the comedi
driver source files.  This was recently updated to allow and strip off a
" * " prefix at the start of each line (well actually, it uses the perl
substitution 's/^ ?\* ?//').

The skel.c file contains an instructional comment block about how to
format this driver comment block, but the updated 'dump_doc' script
mistakenly treats this as a valid driver comment block.  This patch adds
some extra whitespace to stop the instructional comment block being
treated as a valid driver comment block by Comedi's 'dump_doc' script.
Signed-off-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>