bug#23820: 25.1.50; Fix caller to ediff-setup

[Tino Calancha]

> I think that argument is not a hook but just a list of functions, so
> it should suffice to do
>
> @@ -913,7 +916,7 @@ hilit-chg-get-diff-info
>   (let (hilit-e hilit-x hilit-y)
>     (ediff-setup buf-a file-a buf-b file-b
>               nil nil   ; buf-c file-C
> -              'hilit-chg-get-diff-list-hk
> +              '(hilit-chg-get-diff-info-hk)
>               (list (cons 'ediff-job-name 'something))
>               )
>     (ediff-with-current-buffer hilit-e (ediff-really-quit nil))

Yeah, i tried that first but i thought it could be useful for 
documentation adding the new var.
But if
hilit-chg-get-diff-info-hk
it is a list of functions then let's go with the
'(hilit-chg-get-diff-info-hk)
solution.

emacs25 branch wasn't affected because ediff-setup calls run-hooks
(in master branch use 'mapc).