8276121: G1: Remove unused and uninitialized _g1h in g1SATBMarkQueueSet.hpp

Reviewed-by: ayang, tschatzl

Author: lkorinth

src/hotspot/share/gc/g1/g1SATBMarkQueueSet.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -27,13 +27,10 @@
 
 #include "gc/shared/satbMarkQueue.hpp"
 
-class G1CollectedHeap;
 class Monitor;
 class Thread;
 
 class G1SATBMarkQueueSet : public SATBMarkQueueSet {
-  G1CollectedHeap* _g1h;
-
 public:
   G1SATBMarkQueueSet(BufferNode::Allocator* allocator);