hg: jdk/sandbox: Fix race conditation in test and add logging for TestLatestEvent

[erik.gahlin at oracle.com]

Changeset: 3d0a172353fc
Author:    egahlin
Date:      2019-10-21 20:09 +0200
URL:       https://hg.openjdk.java.net/jdk/sandbox/rev/3d0a172353fc

Fix race conditation in test and add logging for TestLatestEvent

! test/jdk/jdk/jfr/api/consumer/recordingstream/TestSetEndTime.java
! test/jdk/jdk/jfr/api/consumer/streaming/TestLatestEvent.java