make the grammar more like scala

Author: WangTaoTheTonic

core/src/main/scala/org/apache/spark/SparkContext.scala

@@ -176,10 +176,8 @@ class SparkContext(config: SparkConf) extends Logging with ExecutorAllocationCli
   logInfo(s"Running Spark version $SPARK_VERSION")
 
   private[spark] val conf = config.clone()
-  val portRetriesConf = conf.getOption("spark.port.maxRetries")
-  if (portRetriesConf.isDefined) {
-    System.setProperty("spark.port.maxRetries", portRetriesConf.get)
-  }
+  conf.getOption("spark.port.maxRetries")
+      .foreach(portRetriesConf => System.setProperty("spark.port.maxRetries", portRetriesConf))
   conf.validateSettings()
 
   /**

yarn/src/main/scala/org/apache/spark/deploy/yarn/ExecutorRunnableUtil.scala

@@ -75,10 +75,9 @@ trait ExecutorRunnableUtil extends Logging {
     // registers with the Scheduler and transfers the spark configs. Since the Executor backend
     // uses Akka to connect to the scheduler, the akka settings are needed as well as the
     // authentication settings.
-    sparkConf.getAll.
-      filter { case (k, v) =>
+    sparkConf.getAll.filter { case (k, v) =>
       k.startsWith("spark.auth") || k.startsWith("spark.akka") || k.equals("spark.port.maxRetries")
-      }.
+    }.
       foreach { case (k, v) => javaOpts += YarnSparkHadoopUtil.escapeForShell(s"-D$k=$v") }
 
     sparkConf.getAkkaConf.