[CORE] Bugfix: LogErr format in DAGScheduler.scala

Author: Zhang, Liye <liye.zhang@intel.com>

Closes #2572 from liyezhang556520/DAGLogErr and squashes the following commits:

5be2491 [Zhang, Liye] Bugfix: LogErr format in DAGScheduler.scala

core/src/main/scala/org/apache/spark/scheduler/DAGScheduler.scala

@@ -1209,7 +1209,7 @@ class DAGScheduler(
             .format(job.jobId, stageId))
       } else if (jobsForStage.get.size == 1) {
         if (!stageIdToStage.contains(stageId)) {
-          logError("Missing Stage for stage with id $stageId")
+          logError(s"Missing Stage for stage with id $stageId")
         } else {
           // This is the only job that uses this stage, so fail the stage if it is running.
           val stage = stageIdToStage(stageId)