ox-extra: Use cl-lib

* contrib/lisp/ox-extra.el (org-latex-header-blocks-filter): Use "cl-"
prefix.

contrib/lisp/ox-extra.el

@@ -56,7 +56,7 @@
 ;;; Code:
 
 (require 'ox)
-(eval-when-compile (require 'cl))
+(require 'cl-lib)
 
 (defun org-latex-header-blocks-filter (backend)
   (when (org-export-derived-backend-p backend 'latex)
@@ -72,8 +72,10 @@
 		       (org-element-property :post-affiliated block)))))))
       (mapc (lambda (pos)
 	      (goto-char (nth 2 pos))
-	      (destructuring-bind
+	      (cl-destructuring-bind
 		  (beg end &rest ignore)
+		  ;; FIXME: `org-edit-src-find-region-and-lang' was
+		  ;; removed in 9c06f8cce (2014-11-11).
 		  (org-edit-src-find-region-and-lang)
 		(let ((contents-lines (split-string
 				       (buffer-substring-no-properties beg end)