org-format-outline-path: Cosmetic fix

* lisp/org.el (org-format-outline-path): Change loop counter.

The old version gives the same result when combined with the other for
clause, but it reads as though the intention is to reach
(length path) rather than (1- (length path)).

lisp/org.el

@@ -11760,7 +11760,7 @@ the default is \"/\"."
 		 (mapconcat
 		  (lambda (s) (replace-regexp-in-string "[ \t]+\\'" "" s))
 		  (loop for head in path
-			for n upto (length path)
+			for n from 0
 			collect (org-add-props
 				    head nil 'face
 				    (nth (% n org-n-level-faces) org-level-faces)))