HDFS-16326. Simplify the code for DiskBalancer (#3663)

Reviewed-by: Viraj Jasani <vjasani@apache.org>
(cherry picked from commit 965e387)

Author: tomscut

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DiskBalancer.java

@@ -808,7 +808,7 @@ private boolean isLessThanNeeded(long blockSize,
       long bytesToCopy = item.getBytesToCopy() - item.getBytesCopied();
       bytesToCopy = bytesToCopy +
           ((bytesToCopy * getBlockTolerancePercentage(item)) / 100);
-      return (blockSize <= bytesToCopy) ? true : false;
+      return blockSize <= bytesToCopy;
     }
 
     /**
@@ -833,7 +833,7 @@ private long getBlockTolerancePercentage(DiskBalancerWorkItem item) {
     private boolean isCloseEnough(DiskBalancerWorkItem item) {
       long temp = item.getBytesCopied() +
           ((item.getBytesCopied() * getBlockTolerancePercentage(item)) / 100);
-      return (item.getBytesToCopy() >= temp) ? false : true;
+      return item.getBytesToCopy() < temp;
     }
 
     /**