private boolean isHdfsAclSet(Table aclTable, String userName) throws IOException {
    return isHdfsAclSet(aclTable, userName, null, null);
  }
Delete namespace tmp directory because it's created by this coprocessor when namespace is
created to make namespace default acl can be inherited by tables. The namespace data
directory is deleted by DeleteNamespaceProcedure, the namespace archive directory is
deleted by HFileCleaner.
hbase-server/src/main/java/org/apache/hadoop/hbase/security/access/SnapshotScannerHDFSAclController.java