doc: correct help for 'bos getlog' -restricted mode

doc: correct help for 'bos getlog' -restricted mode

Commit f085951d39c0d6c1e6a626177c30235704317600 introduced an error in
the bos getlog helpfile.

Modify the helpfile to describe the actual restrictions imposed by
-restricted mode.

Reviewed-on: https://gerrit.openafs.org/12454
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: Benjamin Kaduk <kaduk@mit.edu>
(cherry picked from commit 3af0460a4a6d7bf22e1789fd9e375659e20c3a55)

Change-Id: Ifa544c322e67da712a0bc96b3797e51786e4d399
Reviewed-on: https://gerrit.openafs.org/12476
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>