refactor

$fname = static::downloadFile($manualUrl);
if ($fname !== '') {

    $info = \CFile::MakeFileArray($fname);
    $info['MODULE_ID'] = 'iblock';
    $fileId = \CFile::SaveFile($info, $info['MODULE_ID']);
    if ($fileId) {
        $item->setProperty(static::MANUAL_CODE, $fileId);
    }
}

// new version
public static function downloadManual( $manualUrl )
{
    $fileId = 0;
    if ($manualUrl !== '') {
        $fname = static::downloadFile($manualUrl);
        if ($fname !== '') {

            $info = CFile::MakeFileArray($fname);
            $info['MODULE_ID'] = 'iblock';
            $fileId = CFile::SaveFile($info, $info['MODULE_ID']);
        }
    }
    return $fileId;
}

$fileId = static::downloadManual( $item->getManualUrl() );
if ($fileId) {
    $item->setProperty(static::MANUAL_CODE, $fileId);
}