Matching to Houdini build 18.6.11.

Author: SideFX

src/houdini/lib/H_USD/HUSD/HUSD_Scene.C

@@ -505,7 +505,7 @@ public:
 
 private:
  UT_Map<uint64, RenderTagBucket > myBuckets;
- UT_Map<int, uint64> myPrimBucketMap;
+ UT_Map<uint64, uint64> myPrimBucketMap;
  HUSD_Scene &myScene;
  bool myDirtyFlag = false;
  UT_Lock myLock;