Minor style and comment fixes

Author: holdenk

core/src/main/scala/org/apache/spark/deploy/client/StandaloneAppClient.scala

@@ -39,7 +39,6 @@ import org.apache.spark.util.{RpcUtils, ThreadUtils}
  * Takes a master URL, an app description, and a listener for cluster events, and calls
  * back the listener when various events occur.
  *
- *
  * @param masterUrls Each url should look like spark://host:port.
  */
 private[spark] class StandaloneAppClient(

core/src/main/scala/org/apache/spark/deploy/master/Master.scala

@@ -248,7 +248,7 @@ private[deploy] class Master(
       if (state == RecoveryState.STANDBY) {
         workerRef.send(MasterInStandby)
       } else {
-        // If a worker attempts to decommission that isn't registered ignore it.
+        // We use foreach since if it isn't registered we just skip it.
         idToWorker.get(id).foreach(decommissionWorker)
       }