message: Remove unused variable
  This PR removes a unused variable which leads to a warning during build time.
diff: @@ -21,10 +21,6 @@ limitations under the License.
  namespace tensorflow {
  -namespace {
  -constexpr float kLayerByLayerTreeWeight = 1.0;
  -} // namespace
  -
  // Constructor.
  BoostedTreesEnsembleResource::BoostedTreesEnsembleResource()
  : tree_ensemble_(
  