bullet: Plug memory leaks

Signed-off-by: deflected <deflected@github>

panda/src/bullet/bulletHeightfieldShape.I

@@ -18,7 +18,7 @@ INLINE BulletHeightfieldShape::
 ~BulletHeightfieldShape() {
 
   delete _shape;
-  delete _data;
+  delete [] _data;
 }
 
 /**

panda/src/bullet/bulletTriangleMesh.cxx

@@ -134,6 +134,8 @@ add_geom(const Geom *geom, bool remove_duplicate_vertices, const TransformState
       _mesh->addTriangle(v0, v1, v2, remove_duplicate_vertices);
     }
   }
+
+  delete [] vertices;
 }
 
 /**
@@ -163,6 +165,8 @@ add_array(const PTA_LVecBase3 &points, const PTA_int &indices, bool remove_dupli
 
     _mesh->addTriangle(v0, v1, v2, remove_duplicate_vertices);
   }
+
+  delete [] vertices;
 }
 
 /**