RFR: 8158508: gc/logging/TestUnifiedLoggingSwitchStress.java timeout

[Michail Chernov]

Hi,

Could I have a review for this small change which adds @requires to one 
stress test, please?

http://cr.openjdk.java.net/~mchernov/8158508/webrev.00/
https://bugs.openjdk.java.net/browse/JDK-8158508

Tested locally, test is being excluded with enabled JFR.

Thanks,
Michail