Fix out-of-array-bounds issue in the fsfs-stats tool when processing
format 7 repositories.

* tools/server-side/fsfs-stats.c
  (read_log_rev_or_packfile): Since unused / padding blocks report
                              revision -1, we may only access the
                              revision info for "contentful" items.

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1555440 13f79535-47bb-0310-9956-ffa450edef68
* subversion/libsvn_fs_fs/pack.c
  (auto_pad_block): Fix p2l index entries for unused sections.

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1555441 13f79535-47bb-0310-9956-ffa450edef68