HADOOP-16075. Upgrade checkstyle version to 8.16.

Contributed by Dinesh Chitlangia.

pom.xml

@@ -111,7 +111,7 @@ xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xs
     <maven-bundle-plugin.version>2.5.0</maven-bundle-plugin.version>
     <lifecycle-mapping.version>1.0.0</lifecycle-mapping.version>
     <maven-checkstyle-plugin.version>3.0.0</maven-checkstyle-plugin.version>
-    <checkstyle.version>8.8</checkstyle.version>
+    <checkstyle.version>8.16</checkstyle.version>
     <dependency-check-maven.version>1.4.3</dependency-check-maven.version>
 
     <shell-executable>bash</shell-executable>