How to prevent flycheck from treating my init.el as a package file?

If flycheck-mode is enabled for my init.el, I got the following kinds of errors:

The first line should be of the form: ";;; package --- Summary" (emacs-lisp-checkdoc)...The footer should be: (provide 'init)\n;;; init.el ends here (emacs-lisp-checkdoc)

How can I stop flycheck from treating my init.el as a package?

EDIT

I tried to following minimal start up file:

;; flycheck-mode(require 'flycheck)(global-flycheck-mode)(setq-default flycheck-disabled-checker '(emacs-lisp-checkdoc))

Only flycheck and its dependencies are enabled. emacs-lisp-checkdoc is in the disabled checker list but flycheck still lists errors:

0     warning         The first line should be of the form: ";;; package --- Summary" (emacs-lisp-checkdoc)0     warning         You should have a section marked ";;; Commentary:" (emacs-lisp-checkdoc)2   1 error           Cannot open load file: no such file or directory, flycheck (emacs-lisp)3     warning         You should have a section marked ";;; Code:" (emacs-lisp-checkdoc)5     warning         The footer should be: (provide 'test)\n;;; test.el ends here (emacs-lisp-checkdoc)

I'm using Emacs 24.5.1 and the latest flycheck in the git repository (26snapshot).