Replaced a variable with simple field reference

Author: sarutak

core/src/main/scala/org/apache/spark/util/JsonProtocol.scala

@@ -25,8 +25,6 @@ import scala.collection.Map
 import org.json4s.DefaultFormats
 import org.json4s.JsonDSL._
 import org.json4s.JsonAST._
-
-// Don't remove. It may seem this statement is useless but this is need to parse with Jackson
 import org.json4s.jackson.JsonMethods._
 
 
@@ -207,7 +205,6 @@ private[spark] object JsonProtocol {
   }
 
   def taskInfoToJson(taskInfo: TaskInfo): JValue = {
-    val accumUpdateMap = taskInfo.accumulables
     ("Task ID" -> taskInfo.taskId) ~
     ("Index" -> taskInfo.index) ~
     ("Attempt" -> taskInfo.attempt) ~
@@ -219,7 +216,7 @@ private[spark] object JsonProtocol {
     ("Getting Result Time" -> taskInfo.gettingResultTime) ~
     ("Finish Time" -> taskInfo.finishTime) ~
     ("Failed" -> taskInfo.failed) ~
-    ("Accumulables" -> JArray(accumUpdateMap.map(accumulableInfoToJson).toList))
+    ("Accumulables" -> JArray(taskInfo.accumulables.map(accumulableInfoToJson).toList))
   }
 
   def accumulableInfoToJson(accumulableInfo: AccumulableInfo): JValue = {