vldb_check: print vlentry file offsets

To aid in debugging, consistently print the vlentry database "address"
and the file offset when displaying errors for vlentries.  Print the
vlentry file offsets when printing all the entries with the -entries
option.

Reviewed-on: http://gerrit.openafs.org/9906
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
(cherry picked from commit ccb66323a0a74b35b44aa901a49490a5021d46e0)

Change-Id: I4a3e7296b7b6cd8a228e4d44b591c572bdbb5c70
Reviewed-on: http://gerrit.openafs.org/10269
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>