WordPress - Allow .swf uploads

<?php
  // allow swf uploads
  // (swf uploads are disabled by default as a security hardening measure)
  // code goes in functions.php for your child theme
  add_filter('upload_mimes','allow_swfs');
  function allow_swfs($mimes) {
    if ( function_exists( 'current_user_can' ) )
        $unfiltered = $user ? user_can( $user, 'unfiltered_html' ) : current_user_can( 'unfiltered_html' );
    if ( !empty( $unfiltered ) ) {
        $mimes['swf'] = 'application/x-shockwave-flash';
    }
    return $mimes;
  }