HDFS-16074. Remove an expensive debug string concatenation (apache#3107)

Reviewed-by: Ayush Saxena <[email protected]>
Reviewed-by: Akira Ajisaka <[email protected]>
Reviewed-by: Inigo Goiri <[email protected]>
Reviewed-by: Hui Fei <[email protected]>
Reviewed-by: Viraj Jasani <[email protected]>
Reviewed-by: litao <[email protected]>

Author: jojochuang

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

@@ -483,9 +483,10 @@ private synchronized void writeChunkPrepare(int buflen,
       currentPacket = createPacket(packetSize, chunksPerPacket, getStreamer()
           .getBytesCurBlock(), getStreamer().getAndIncCurrentSeqno(), false);
       DFSClient.LOG.debug("WriteChunk allocating new packet seqno={},"
-              + " src={}, packetSize={}, chunksPerPacket={}, bytesCurBlock={}",
+              + " src={}, packetSize={}, chunksPerPacket={}, bytesCurBlock={},"
+              + " output stream={}",
           currentPacket.getSeqno(), src, packetSize, chunksPerPacket,
-          getStreamer().getBytesCurBlock() + ", " + this);
+          getStreamer().getBytesCurBlock(), this);
     }
   }