[SPARK-17894][HOTFIX] Fix broken build from

The named parameter in an overridden class isn't supported in Scala 2.10 so was breaking the build.

cc zsxwing

Author: Kay Ousterhout <kayousterhout@gmail.com>

Closes #15617 from kayousterhout/hotfix.

core/src/test/scala/org/apache/spark/scheduler/FakeTask.scala

@@ -22,7 +22,7 @@ import org.apache.spark.TaskContext
 class FakeTask(
     stageId: Int,
     partitionId: Int,
-    prefLocs: Seq[TaskLocation] = Nil) extends Task[Int](stageId, stageAttemptId = 0, partitionId) {
+    prefLocs: Seq[TaskLocation] = Nil) extends Task[Int](stageId, 0, partitionId) {
   override def runTask(context: TaskContext): Int = 0
   override def preferredLocations: Seq[TaskLocation] = prefLocs
 }