RFR(S, TESTONLY): JDK-8081576 serviceability/sa tests fail due to LingeredApp process fails to start

[Dmitry Samersoff]

Everybody,

Please review a test-only fix:

http://cr.openjdk.java.net/~dsamersoff/JDK-8081576/webrev.01/

LingeredApp can throw an exception during initialization if it not able
to create a lock file for some reason. This exception cause NPE later,
when the test attempts to stop LingeredApp and original exception get lost.

Fixing it by adding static stopApp(app) method with null pointer check
inside.


-- 
Dmitry Samersoff
Oracle Java development team, Saint Petersburg, Russia
* I would love to change the world, but they won't give me the sources.