svnauthz: Fix path canonicalizations.

* tools/server-side/svnauthz.c
  (subcommand_accessof): Remove poor mans attempt at canonicalizing a fspath.
  (sub_main): --path argument is always a fspath so use
    svn_fspath__canonicalize().  opt_state.authz_file can be a uri, dirent,
    or fspath depending on context, use the proper functions in the right
    context.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1428701 13f79535-47bb-0310-9956-ffa450edef68