HDFS-16073. Remove redundant RPC requests for getFileLinkInfo in ClientNamenodeProtocolTranslatorPB. Contributed by lei w.

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocolPB/ClientNamenodeProtocolTranslatorPB.java

@@ -939,9 +939,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
         .setSrc(src).build();
     try {
       GetFileLinkInfoResponseProto result = rpcProxy.getFileLinkInfo(null, req);
-      return result.hasFs() ?
-          PBHelperClient.convert(rpcProxy.getFileLinkInfo(null, req).getFs()) :
-          null;
+      return result.hasFs() ? PBHelperClient.convert(result.getFs()) : null;
     } catch (ServiceException e) {
       throw ProtobufHelper.getRemoteException(e);
     }