HDFS-12932. Fix confusing LOG message for block replication. Contributed by Chao Sun.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirAttrOp.java

@@ -414,9 +414,12 @@ public class FSDirAttrOp {
       if (oldBR > targetReplication) {
         FSDirectory.LOG.info("Decreasing replication from {} to {} for {}",
                              oldBR, targetReplication, iip.getPath());
-      } else {
+      } else if (oldBR < targetReplication) {
         FSDirectory.LOG.info("Increasing replication from {} to {} for {}",
                              oldBR, targetReplication, iip.getPath());
+      } else {
+        FSDirectory.LOG.info("Replication remains unchanged at {} for {}",
+                             oldBR, iip.getPath());
       }
     }
     return file.getBlocks();