vfsck: Fix roken fallout

vfsck: Fix roken fallout

Including roken.h in vfsck sources pulls in some more modern headers
that vfsck code isn't used to. Accommodate:

 - Prevent roken.h from pulling in dirent.h so we don't conflict with
   the old-style directory defines for HP-UX. Also move the inclusion
   of the old-style directory defines to before roken.h, so we have
   the directory types defined in roken.h.

 - Remove some prototypes so the don't conflict with the prototypes in
   system headers.

 - Remove a couple of bizarre vprintf invocations, as they conflict
   with the actual vprintf definitions.

Change-Id: Ifd7cd2544e75ed49b93ab491c4acadcb18528315
Reviewed-on: http://gerrit.openafs.org/4472
Reviewed-by: Simon Wilkinson <sxw@inf.ed.ac.uk>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Tested-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Derrick Brashear <shadow@dementia.org>