ol.el: Fix confusing variable name

* ol.el (org-link--open-help): Fix a confusing variable name.  No
behavior changes.

TINYCHANGE

lisp/ol.el

@@ -1335,8 +1335,8 @@ PATH is the sexp to evaluate, as a string."
   "Open a \"help\" type link.
 PATH is a symbol name, as a string."
   (pcase (intern path)
-    ((and (pred fboundp) variable) (describe-function variable))
-    ((and (pred boundp) function) (describe-variable function))
+    ((and (pred fboundp) function) (describe-function function))
+    ((and (pred boundp) variable) (describe-variable variable))
     (name (user-error "Unknown function or variable: %s" name))))
 
 (org-link-set-parameters "help" :follow #'org-link--open-help)