org-mouse: Fix keyword selection menu

* lisp/org-mouse.el (org-mouse-keyword-menu): Fix void-variable error
when selecting todo keyword.

Reported in https://list.orgmode.org/CAFChFyjzuBtr8BeGTb195AVoGbUKFtXf35vvv-r0mzOy0wvZ2Q@mail.gmail.com/T/#u

lisp/org-mouse.el

@@ -295,7 +295,7 @@ nor a function, elements of KEYWORDS are used directly."
 	      ((functionp itemformat) (funcall itemformat keyword))
 	      ((stringp itemformat) (format itemformat keyword))
 	      (t keyword))
-	     (list 'funcall function keyword)
+	     `(funcall #',function ,keyword)
 	     :style (cond
 		     ((null selected) t)
 		     ((functionp selected) 'toggle)