RFR 8064441: java/lang/management/ThreadMXBean/Locks.java fails intermittently, blocked on wrong object

[Jaroslav Bachorik]

Please, review the following test change

Issue : https://bugs.openjdk.java.net/browse/JDK-8064441
Webrev: http://cr.openjdk.java.net/~jbachorik/8064441/webrev.00

The test fails because of System.out.println() may induce unexpected 
locking. The solution is to use an already existing LockFreeLogManager 
library class to collect the logs in the lock-free manner and print the 
logs only after all the test code has been run.

Thanks,

-JB-