move driverlabels out

resource-managers/mesos/src/main/scala/org/apache/spark/scheduler/cluster/mesos/MesosClusterScheduler.scala

@@ -568,15 +568,19 @@ private[spark] class MesosClusterScheduler(
     offer.remainingResources = finalResources.asJava
 
     val appName = desc.conf.get("spark.app.name")
-    val taskInfo = TaskInfo.newBuilder()
+
+    val driverLabels = MesosProtoUtils.mesosLabels(desc.conf.get(config.DRIVER_LABELS)
+      .getOrElse(""))
+
+    TaskInfo.newBuilder()
       .setTaskId(taskId)
       .setName(s"Driver for ${appName}")
       .setSlaveId(offer.offer.getSlaveId)
       .setCommand(buildDriverCommand(desc))
       .setContainer(getContainerInfo(desc))
       .addAllResources(cpuResourcesToUse.asJava)
       .addAllResources(memResourcesToUse.asJava)
-      .setLabels(MesosProtoUtils.mesosLabels(desc.conf.get(config.DRIVER_LABELS).getOrElse("")))
+      .setLabels(driverLabels)
       .build
   }