Hyphens should be replaced with underscores in entity id when added to theme_hook_suggestions

Code with bug:

if ($id = entity_id($entity_type, $entity)) {
    $variables['theme_hook_suggestions'][] = $entity_type . '__' . $id;
}

If $id contains "-" it's not converted to "_" and template ignored.

Description from theme_get_suggestions function docs:

// Remove slashes or null per SA-CORE-2009-003 and change - (hyphen) to _
// (underscore).
//
// When we discover templates in @see drupal_find_theme_templates,
// hyphens (-) are converted to underscores (_) before the theme hook
// is registered. We do this because the hyphens used for delimiters
// in hook suggestions cannot be used in the function names of the
// associated preprocess functions. Any page templates designed to be used
// on paths that contain a hyphen are also registered with these hyphens
// converted to underscores so here we must convert any hyphens in path
// arguments to underscores here before fetching theme hook suggestions
// to ensure the templates are appropriately recognized.
$arg = str_replace(array("/", "\\", "\0", '-'), array('', '', '', '_'), $arg);