Added an extra check to MLU bounds

Thanks to Ibrahim el-sayed for spotting the bug
void* Type_ColorantTable_Dup(struct _cms_typehandler_struct* self, const void* Ptr, cmsUInt32Number n)
{
    cmsNAMEDCOLORLIST* nc = (cmsNAMEDCOLORLIST*) Ptr;
    return (void*) cmsDupNamedColorList(nc);

    cmsUNUSED_PARAMETER(n);
    cmsUNUSED_PARAMETER(self);
}

void* Type_ColorantTable_Dup(struct _cms_typehandler_struct* self, const void* Ptr, cmsUInt32Number n)
{
    cmsNAMEDCOLORLIST* nc = (cmsNAMEDCOLORLIST*) Ptr;
    return (void*) cmsDupNamedColorList(nc);

    cmsUNUSED_PARAMETER(n);
    cmsUNUSED_PARAMETER(self);
}
