fix-pkg.el

(dolist (dir (directory-files "elpa" t "^[^.]"))
  (let ((name (file-name-nondirectory dir)))
    (when (string-match "\\(.+\\)-[^-]+\\'" name)
      (let ((file (expand-file-name (concat (match-string 1 name) "-pkg.el") dir)))
	(with-temp-file file
	  (save-excursion (insert-file-contents file))
	  (when (looking-at "(define-package \\([^\" ]+\\)")
	    (message "Fixing %s..." file)
	    (replace-match "\"\\1\"" t nil nil 1)
	    (message "Fixing %s...done" file)))))))

$ cd ~/.emacs.d    # or ~/.config/emacs
$ wget https://gist.githubusercontent.com/tarsius/ee51369ee7e07821e45e123f4067a5db/raw/d8c569a82089a8a53c08ee9621211e29a2264737/fix-pkg.el
$ emacs -Q --batch --load fix-pkg.el

This assumes that the default installation location is used. If you use something else, then you have to replace the "elpa" with whatever is correct in your case.