HDFS-9906. Remove spammy log spew when a datanode is restarted. (Contributed by Brahma Reddy Battula)

(cherry picked from commit 02949b2151f1eecce3e1bcdbbec1afac164a6065)

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockManager.java

@@ -2571,7 +2571,7 @@ public class BlockManager {
       corruptReplicas.removeFromCorruptReplicasMap(block, node,
           Reason.GENSTAMP_MISMATCH);
       curReplicaDelta = 0;
-      blockLog.warn("BLOCK* addStoredBlock: Redundant addStoredBlock request"
+      blockLog.debug("BLOCK* addStoredBlock: Redundant addStoredBlock request"
               + " received for {} on node {} size {}", storedBlock, node,
           storedBlock.getNumBytes());
     }