volser: detect eof in dump stream while reading acl

volser: detect eof in dump stream while reading acl

Detect an EOF condition while reading the ACL in a dump stream
and return a restore error, instead of filling the ACL with
0xFF and then failing the restore due to an invalid tag.

Reviewed-on: http://gerrit.openafs.org/11703
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
(cherry picked from commit ed52d65fe98549e13023e0a8997da479b626085a)

Change-Id: I9aacd635b8bbf89923db0121639d5112ab775c19
Reviewed-on: https://gerrit.openafs.org/12185
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>