You can do something like the following at that codeblock:
```javascript
var phoneNumberAdditionalInfo = '';
if (contact && contact.matchingTel) {
    phoneNumberAdditionalInfo =
    Utils.getPhoneNumberAdditionalInfo(contact.matchingTel);
} else if (voicemail || emergency) {
    // Check if the number is an emergency or a voicemail
    // number and set the appropriate label
    phoneNumberAdditionalInfo =
       voicemail ? this._('voiceMail') :
          (emergency ? this._('emergencyNumber') : '');
}
if (phoneNumberAdditionalInfo && phoneNumberAdditionalInfo.length) {
    var addInfo = document.createElement('p');
    addInfo.className = 'call-additional-info';
    addInfo.textContent = phoneNumberAdditionalInfo;
}
```
I think it is much cleaner and easier to maintain this way, since you are setting the `call-additional-info` in only one place.