change the API name since we support not only HDFS and local file system

jvm-packages/xgboost4j-spark/src/main/scala/ml/dmlc/xgboost4j/scala/spark/XGBoost.scala

@@ -128,7 +128,8 @@ object XGBoost extends Serializable {
    * @param modelPath The path of the file representing the model
    * @return The loaded model
    */
-  def loadModelFromHadoop(modelPath: String)(implicit sparkContext: SparkContext): XGBoostModel = {
+  def loadModelFromHadoopFile(modelPath: String)(implicit sparkContext: SparkContext):
+      XGBoostModel = {
     val path = new Path(modelPath)
     val dataInStream = path.getFileSystem(sparkContext.hadoopConfiguration).open(path)
     val xgBoostModel = new XGBoostModel(SXGBoost.loadModel(dataInStream))

jvm-packages/xgboost4j-spark/src/main/scala/ml/dmlc/xgboost4j/scala/spark/XGBoostModel.scala

@@ -49,7 +49,7 @@ class XGBoostModel(booster: Booster)(implicit val sc: SparkContext) extends Seri
    *
    * @param modelPath The model path as in Hadoop path.
    */
-  def saveModelToHadoop(modelPath: String): Unit = {
+  def saveModelToHadoopFile(modelPath: String): Unit = {
     val path = new Path(modelPath)
     val outputStream = path.getFileSystem(sc.hadoopConfiguration).create(path)
     booster.saveModel(outputStream)