doc/org-manual.org: Fix typo

* doc/org-manual.org (Using the Mapping API): Fix incorrect
description of the return value of `org-map-entries'.  The return
value is a list, not alist.

Reported-by: Ignacio Casso <ignaciocasso@hotmail.com>
Link: https://orgmode.org/list/PAXPR06MB7760636DC6C66FB22B27E692C62F9@PAXPR06MB7760.eurprd06.prod.outlook.com

doc/org-manual.org

@@ -21688,7 +21688,7 @@ Call {{{var(FUNC)}}} at each headline selected by {{{var(MATCH)}}} in
 
 {{{var(FUNC)}}} is a function or a Lisp form.  With point positioned
 at the beginning of the headline, call the function without arguments.
-Org returns an alist of return values of calls to the function.
+Org returns a list of return values of calls to the function.
 
 To avoid preserving point, Org wraps the call to {{{var(FUNC)}}} in
 ~save-excursion~ form.  After evaluation, Org moves point to the end