HDFS-15698. Fix the typo of dfshealth.html after HDFS-15358 (#2495)

hadoop-hdfs-project/hadoop-hdfs/src/main/webapps/hdfs/dfshealth.html

@@ -357,7 +357,7 @@
     <td></td>
     <td></td>
     <td></td>
-    <td></td>>
+    <td></td>
   </tr>
   {/DeadNodes}
 </table>