On the fsx-id branch: Remove some cached-data layer internal use of svn_fs_t.

* subversion/libsvn_fs_x/cached_data.c
  (read_dir_entries): Switch the ID parameter to new noderev ID type;
                      update the error handling code.
  (get_dir_contents): Update caller.

git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/fsx-id@1645610 13f79535-47bb-0310-9956-ffa450edef68