message: Update split_handler_ops.cc
  Removed unused variables best_dimension_idx & dimension_id from split_handler_ops.cc
diff: @@ -538,7 +538,6 @@ class BuildSparseInequalitySplitsOp : public OpKernel {
  partition_boundaries[non_empty_partitions[root_idx]];
  float best_gain = std::numeric_limits<float>::lowest();
  - int32 best_dimension_idx = 0;
  bool default_right = false;
  int32 best_element_idx = 0;
  @@ -571,7 +570,6 @@ class BuildSparseInequalitySplitsOp : public OpKernel {
  // Iterate through dimensions.
  for (int j = 0; j < dimension_boundaries.size() - 1; ++j) {
  const DimensionBoundary& dimension_and_start = dimension_boundaries[j];
  - const int32 dimension_id = dimension_and_start.dimension_id;
  int start_index = dimension_and_start.start_index;
  // Even for the last dimension, we always have additional dummy
  @@ -630,7 +628,6 @@ class BuildSparseInequalitySplitsOp : public OpKernel {
  best_right_node_stats = right_stats_default_left;
  best_element_idx = element_idx;
  default_right = false;
  - best_dimension_idx = dimension_id;
  }
  }
  // Consider calculating the default direction only when there were
  @@ -648,7 +645,6 @@ class BuildSparseInequalitySplitsOp : public OpKernel {
  best_right_node_stats = right_stats_default_right;
  best_element_idx = element_idx;
  default_right = true;
  - best_dimension_idx = dimension_id;
  }
  }
  }
  