message: adjust MakeTieredDbname to consistently use std::string::size() instead of some calls to length() and some to size()
diff: @@ -282,7 +282,7 @@ MakeTieredDbname(
  Options & options) // input/output ... writable Options, tiered values changed
  {
  // case for "", used with internal calls to DestroyDB
  - if (0==dbname.length() && 0!=options.tiered_fast_prefix.length())
  + if (0==dbname.size() && 0!=options.tiered_fast_prefix.size())
  {
  // do NOTHING ... options already initialized
  } // if
  