hg: shenandoah/jdk8u/hotspot: [backport] Cleanup: update-refs check in_collection_set twice

[ashipile at redhat.com]

Changeset: 390e6ca36177
Author:    shade
Date:      2017-05-12 13:03 +0200
URL:       http://hg.openjdk.java.net/shenandoah/jdk8u/hotspot/rev/390e6ca36177

[backport] Cleanup: update-refs check in_collection_set twice

! src/share/vm/gc_implementation/shenandoah/shenandoahHeap.cpp