YARN-2901 addendum: Fixed findbugs warning caused by previously patch

(cherry picked from commit ba9ee22ca4ed2c5ff447b66b2e2dfe25f6880fe0)

hadoop-yarn-project/hadoop-yarn/dev-support/findbugs-exclude.xml

@@ -461,5 +461,14 @@
     <Method name="recoverContainersOnNode" />
     <Bug pattern="RCN_REDUNDANT_NULLCHECK_OF_NONNULL_VALUE" />
   </Match>
-
+  
+  <!-- Following fields are used in ErrorsAndWarningsBlock, which is not a part of analysis of findbugs -->
+  <Match>
+    <Class name="org.apache.hadoop.yarn.util.Log4jWarningErrorMetricsAppender$Element" />
+    <Or>
+      <Field name="count" />
+      <Field name="timestampSeconds" />
+    </Or>
+    <Bug pattern="URF_UNREAD_PUBLIC_OR_PROTECTED_FIELD" />
+  </Match>
 </FindBugsFilter>