fix blanks.

Author: hfutatzhanghb

hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/router/RouterRpcClient.java

@@ -227,7 +227,7 @@ public RouterRpcClient(Configuration conf, Router router,
     }
     this.lastActiveNNRefreshTimes = new ConcurrentHashMap<>();
   }
-  
+
   protected void initConcurrentCallExecutorService(Configuration conf) {
     int numThreads = conf.getInt(
         RBFConfigKeys.DFS_ROUTER_CLIENT_THREADS_SIZE,

hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/router/async/RouterAsyncRpcClient.java

@@ -118,7 +118,7 @@ public RouterAsyncRpcClient(Configuration conf,
 
   @Override
   protected void initConcurrentCallExecutorService(Configuration conf) {
-    // No need to initialize the thread pool for concurrent call. 
+    // No need to initialize the thread pool for concurrent call.
   }
 
   /**