DFSClient#mkdirs and DFSClient#primitiveMkdir should use default directory permission

  public boolean mkdirs(String src, FsPermission permission,
      boolean createParent) throws IOException {
    if (permission == null) {
      permission = FsPermission.getDefault();
    }

  public boolean primitiveMkdir(String src, FsPermission absPermission, 
    boolean createParent)
    throws IOException {
    checkOpen();
    if (absPermission == null) {
      absPermission = 
        FsPermission.getDefault().applyUMask(dfsClientConf.uMask);
    }