hg: jdk/sandbox: 8212025: Remove collector_present variable from ThreadHeapSampler

[chris.hegarty at oracle.com]

Changeset: 896a556de423
Author:    jcbeyler
Date:      2018-10-11 12:41 -0700
URL:       http://hg.openjdk.java.net/jdk/sandbox/rev/896a556de423

8212025: Remove collector_present variable from ThreadHeapSampler
Summary: Remove unused variable from ThreadHeapSampler
Reviewed-by: tschatzl, pliden

! src/hotspot/share/runtime/threadHeapSampler.hpp