EXA bug: Calling FinishAccess on pixmap 0xaf06d008 with index 1 while it should have been (nil).

[Maarten Maathuis]

> +    /* If slot for this index is taken, find an empty slot */
> +    if (pExaScr->access[index].pixmap) {
> +       for (index = EXA_NUM_PREPARE_INDICES - 1; index >= 0; index--)
> +           if (!pExaScr->access[index].pixmap)
>                break;
> +    }

Maybe add a note in the headerfile that people cannot assume that the
word src or dst has any meaning with regards to usage (wrt to specific
optimisations).