Remove unordered feature calculation in labeledPointToTreePoint

mllib/src/main/scala/org/apache/spark/mllib/tree/impl/TreePoint.scala

@@ -55,17 +55,15 @@ private[tree] object TreePoint {
       input: RDD[LabeledPoint],
       bins: Array[Array[Bin]],
       metadata: DecisionTreeMetadata): RDD[TreePoint] = {
-    // Construct arrays for featureArity and isUnordered for efficiency in the inner loop.
+    // Construct arrays for featureArity for efficiency in the inner loop.
     val featureArity: Array[Int] = new Array[Int](metadata.numFeatures)
-    val isUnordered: Array[Boolean] = new Array[Boolean](metadata.numFeatures)
     var featureIndex = 0
     while (featureIndex < metadata.numFeatures) {
       featureArity(featureIndex) = metadata.featureArity.getOrElse(featureIndex, 0)
-      isUnordered(featureIndex) = metadata.isUnordered(featureIndex)
       featureIndex += 1
     }
     input.map { x =>
-      TreePoint.labeledPointToTreePoint(x, bins, featureArity, isUnordered)
+      TreePoint.labeledPointToTreePoint(x, bins, featureArity)
     }
   }
 
@@ -74,13 +72,11 @@ private[tree] object TreePoint {
    * @param bins      Bins for features, of size (numFeatures, numBins).
    * @param featureArity  Array indexed by feature, with value 0 for continuous and numCategories
    *                      for categorical features.
-   * @param isUnordered  Array index by feature, with value true for unordered categorical features.
    */
   private def labeledPointToTreePoint(
       labeledPoint: LabeledPoint,
       bins: Array[Array[Bin]],
-      featureArity: Array[Int],
-      isUnordered: Array[Boolean]): TreePoint = {
+      featureArity: Array[Int]): TreePoint = {
     val numFeatures = labeledPoint.features.size
     val arr = new Array[Int](numFeatures)
     var featureIndex = 0