RFR: 8031766: jstatd nightly tests failing with Expected one jstatd process, got 2. Test will be canceled.

[Yekaterina Kantserova]

Hi,

Could I please have a review of this fix.

webrev: http://cr.openjdk.java.net/~ykantser/8031766/webrev.00/
bug: https://bugs.openjdk.java.net/browse/JDK-8031766

The bug is not visible. But short summary is as follows. 
sun/tools/jstatd/TestJstatdPort.java, TestJstatdPortAndServer.java, 
TestJstatdServer.java have been failing because they expect only one 
jstad process running. I've added a unique identifier for the jstad 
process tests start. So the tests will no more care about how many other 
jstad processes are running.

Thanks,
Katja