Preprocess the poll_bar theme hook.
Inputs: $title, $votes, $total_votes, $voted, $block
function template_preprocess_poll_bar(&$variables) {
if ($variables['block']) {
$variables['theme_hook_suggestions'][] = 'poll_bar__block';
}
$variables['title'] = check_plain($variables['title']);
$variables['percentage'] = round($variables['votes'] * 100 / max($variables['total_votes'], 1));
}