RFR(xxs): 8185262: Keep default logging for Metaspace OOM short and concise

[Thomas Stüfe]

Hi all,

may I have please reviews for this very tiny change:

bug: https://bugs.openjdk.java.net/browse/JDK-8185262
webrev: http://cr.openjdk.java.net/~stuefe/webrevs/
8185262-keep-metaspace-oom-log-short-for-default/webrev.00/webrev/

On Metaspace OOM, we dump all metaspace chunks in use. This can be very
lengthy. It would be nice if this part of logging were restricted to a
higher loglevel. In this change, I restrict it to debug.

Kind Regards, Thomas