hg: shenandoah/jdk9/hotspot: Cleanup: update-refs check in_collection_set twice

[ashipile at redhat.com]

Changeset: 71ef78a756e7
Author:    shade
Date:      2017-05-12 12:51 +0200
URL:       http://hg.openjdk.java.net/shenandoah/jdk9/hotspot/rev/71ef78a756e7

Cleanup: update-refs check in_collection_set twice

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