--wsrep-recover should print determined recovery position to stdout, not stderr

When calling mariadbd --wsrep-recover to have the server process only do necessary initialization, including crash recovery where needed, the actual recovery position result should be printed to stdout, not stderr (or the configured error log file).

It should be possible to just get the requested information printed without startup log message clutter by e.g.

mariadbd --wsrep-recover 2>/dev/null