Fix documentation bugs.

lisp/org-irc.el

@@ -27,7 +27,7 @@
 ;; Org-mode loads this module by default - if this is not what you want,
 ;; configure the variable `org-modules'.
 ;;
-;; Please customize the variable `org-default-extensions' to select
+;; Please customize the variable `org-modules' to select
 ;; extensions you would like to use, and to deselect those which you don't
 ;; want.
 ;;

lisp/org.el

@@ -125,7 +125,7 @@ With prefix arg HERE, insert it at point."
   "Have the modules been loaded already?")
 
 (defun org-load-modules-maybe (&optional force)
-  "Load all extensions listed in `org-default-extensions'."
+  "Load all extensions listed in `org-modules'."
   (when (or force (not org-modules-loaded))
     (mapc (lambda (ext)
 	    (condition-case nil (require ext)