jmx-dev RFR (XXS): JDK-8174855 Quarantine failing test jdk/test/sun/management/HotspotRuntimeMBean/GetSafepointSyncTime.java

[George Triantafillou]

Please review this very small fix for JDK-8174855:

JBS: https://bugs.openjdk.java.net/browse/JDK-8174855
open webrev: http://cr.openjdk.java.net/~gtriantafill/8174855/webrev/ 
<http://cr.openjdk.java.net/%7Egtriantafill/8174855/webrev/>

The test was added to ProblemList.txt.  Thanks.

-George