On the log-addressing branch:  Follow-up to r1509609.

* subversion/libsvn_fs_fs/fs_fs.c
  (read_format): fix typo commentary and error string;
                 fix missing indirection in error condition;
                 fix parameters provided to error message

git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/log-addressing@1509627 13f79535-47bb-0310-9956-ffa450edef68