Fix various bugs in the authz pool.

* subversion/libsvn_repos/authz_pool.c
  (svn_repos__authz_pool_get): use the correct paths and pools;
                               destroy unused temporary pool

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1541278 13f79535-47bb-0310-9956-ffa450edef68