HDFS-10947. Correct the API name for truncate in webhdfs document. Contributed by Surendra Singh Lilhore

hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/WebHDFS.md

@@ -172,7 +172,7 @@ The HTTP REST API supports the complete [FileSystem](../../api/org/apache/hadoop
 *   HTTP POST
     * [`APPEND`](#Append_to_a_File) (see [FileSystem](../../api/org/apache/hadoop/fs/FileSystem.html).append)
     * [`CONCAT`](#Concat_Files) (see [FileSystem](../../api/org/apache/hadoop/fs/FileSystem.html).concat)
-    * [`TRUNCATE`](#Truncate_a_File) (see [FileSystem](../../api/org/apache/hadoop/fs/FileSystem.html).concat)
+    * [`TRUNCATE`](#Truncate_a_File) (see [FileSystem](../../api/org/apache/hadoop/fs/FileSystem.html).truncate)
 *   HTTP DELETE
     * [`DELETE`](#Delete_a_FileDirectory) (see [FileSystem](../../api/org/apache/hadoop/fs/FileSystem.html).delete)
     * [`DELETESNAPSHOT`](#Delete_Snapshot) (see [FileSystem](../../api/org/apache/hadoop/fs/FileSystem.html).deleteSnapshot)