fix review findings

Change-Id: If5a53df72c616d8b54662619426f5c8f34a9c0c0

Author: peter-toth

sql/hive/src/main/scala/org/apache/spark/sql/hive/hiveUDFs.scala

@@ -340,7 +340,7 @@ private[hive] case class HiveUDAFFunction(
     resolver.getEvaluator(parameterInfo)
   }
 
-  case class Mode(evaluator: GenericUDAFEvaluator, objectInspector: ObjectInspector)
+  private case class Mode(evaluator: GenericUDAFEvaluator, objectInspector: ObjectInspector)
 
   // The UDAF evaluator used to consume raw input rows and produce partial aggregation results.
   // Hive `ObjectInspector` used to inspect partial aggregation results.

sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveUDFSuite.scala

@@ -639,10 +639,9 @@ class HiveUDFSuite extends QueryTest with TestHiveSingleton with SQLTestUtils {
     }
   }
 
-  test("constant argument expecting Hive UDF") {
-    val testData = spark.range(10).toDF()
+  test("SPARK-25768 constant argument expecting Hive UDF") {
     withTempView("inputTable") {
-      testData.createOrReplaceTempView("inputTable")
+      spark.range(10).createOrReplaceTempView("inputTable")
       withUserDefinedFunction("testGenericUDAFPercentileApprox" -> false) {
         val numFunc = spark.catalog.listFunctions().count()
         sql(s"CREATE FUNCTION testGenericUDAFPercentileApprox AS '" +