Change some add-to-list calls to add-hook calls

elisp/firejail-mode.el

@@ -839,8 +839,7 @@ Return a list of the formatted doc and a summary."
   "Major mode for editing firejail profiles."
   :group 'firejail-mode
   :syntax-table firejail-profile-syntax-table
-  (add-to-list (make-local-variable 'completion-at-point-functions)
-               #'firejail-profile-capf)
+  (add-hook 'completion-at-point-functions #'firejail-profile-capf nil t)
   (setq-local font-lock-defaults '(firejail-profile-font-lock-keywords)
               comment-start "#"
               comment-end ""