HDFS-8749. Fix findbugs warnings in BlockManager.java. Contributed by Brahma Reddy Battula.

(cherry picked from commit d66302ed9b2c25b560d8319d6d755aee7cfa4d67)

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -690,6 +690,9 @@ Release 2.8.0 - UNRELEASED
     HDFS-8729. Fix TestFileTruncate#testTruncateWithDataNodesRestartImmediately
     which occasionally failed. (Walter Su via jing9)
 
+    HDFS-8749. Fix findbugs warnings in BlockManager.java.
+    (Brahma Reddy Battula via aajisaka)
+
 Release 2.7.2 - UNRELEASED
 
   INCOMPATIBLE CHANGES

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

@@ -3585,8 +3585,6 @@ public class BlockManager implements BlockStatsMXBean {
       String src, BlockInfo[] blocks) {
     for (BlockInfo b: blocks) {
       if (!b.isComplete()) {
-        final BlockInfoUnderConstruction uc =
-            (BlockInfoUnderConstruction)b;
         final int numNodes = b.numNodes();
         final int min = getMinStorageNum(b);
         final BlockUCState state = b.getBlockUCState();