RFR(XS): 8057686: Clean up ProblemList.txt

[Yekaterina Kantserova]

Hi,

Could I please have a review of this fix for ProblemList.txt.

bug: https://bugs.openjdk.java.net/browse/JDK-8057686
webrev: http://cr.openjdk.java.net/~ykantser/8057686/webrev.00/

Thanks,
Katja