HBASE-24992 log after Generator success when running ITBLL (#2358)

Signed-off-by: Guanghao Zhang <zghao@apache.org>

hbase-it/src/test/java/org/apache/hadoop/hbase/test/IntegrationTestBigLinkedList.java

@@ -1549,6 +1549,7 @@ public class IntegrationTestBigLinkedList extends IntegrationTestBase {
           throw new RuntimeException("Generator.verify failed");
         }
       }
+      LOG.info("Generator finished with success. Total nodes=" + numNodes);
     }
 
     protected void runVerify(String outputDir,