HDFS-11249. Redundant toString() in DFSConfigKeys.java. Contributed by Jagadesh Kiran N.

(cherry picked from commit 36947f79ba66bf8ce150813e5dc1d06c789f2b2a)

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSConfigKeys.java

@@ -228,7 +228,7 @@ public class DFSConfigKeys extends CommonConfigurationKeys {
      need to update the literal here as well as TestDFSConfigKeys.
    */
   public static final String  DFS_WEBHDFS_AUTHENTICATION_FILTER_DEFAULT =
-      "org.apache.hadoop.hdfs.web.AuthFilter".toString();
+      "org.apache.hadoop.hdfs.web.AuthFilter";
   @Deprecated
   public static final String  DFS_WEBHDFS_USER_PATTERN_KEY =
       HdfsClientConfigKeys.DFS_WEBHDFS_USER_PATTERN_KEY;