RFR: Cleanup: update-refs check in_collection_set twice

[Aleksey Shipilev]

Hi,

Minor cleanup in update-refs handling, do in_collection_set check once:

diff -r d5d4cc781486 src/share/vm/gc/shenandoah/shenandoahHeap.cpp
--- a/src/share/vm/gc/shenandoah/shenandoahHeap.cpp	Thu May 11 21:14:39 2017 +0200
+++ b/src/share/vm/gc/shenandoah/shenandoahHeap.cpp	Fri May 12 12:43:18 2017 +0200
@@ -2400,15 +2400,16 @@
   void work(uint worker_id) {
     ShenandoahHeapRegion* r = _regions->claim_next();
     while (r != NULL) {
-      if (! _heap->in_collection_set(r) &&
-          ! r->is_empty()) {
-        _heap->marked_object_oop_safe_iterate(r, &cl);
-      } else if (_heap->in_collection_set(r)) {
+      if (_heap->in_collection_set(r)) {
         HeapWord* bottom = r->bottom();
         HeapWord* top = _heap->complete_top_at_mark_start(r->bottom());
         if (top > bottom) {
           _heap->complete_mark_bit_map()->clear_range_large(MemRegion(bottom,
top));
         }
+      } else {
+        if (!r->is_empty()) {
+          _heap->marked_object_oop_safe_iterate(r, &cl);
+        }
       }
       if (_heap->cancelled_concgc()) {
         return;

Thanks,
-Aleksey