RFR 8040748: [TESTBUG] Exclude failing (serviceability) jtreg tests using @ignore

[Mikael Auno]

Please, review the following fix adding the @ignore tag to a couple of
serviceability tests

Issue:  https://bugs.openjdk.java.net/browse/JDK-8040748
Webrev: http://cr.openjdk.java.net/~miauno/8040748/webrev.00/

Thanks,
Mikael