Fix for bug preventing carts from synchronising

[TroyPatteson]

Carts no longer synchronise due to a bug introduced in commit dcee0f1. The issue is in the _processCartLines() method of app/code/community/Ebizmarts/MailChimp/Model/Api/Carts.php as shown below:

        return array('lines' => $lines, $count = $itemCount);

The fix is simply:

        return array('lines' => $lines, 'count' => $itemCount);

[SantiParagarino]

Thank you for your feedback @TroyPatteson
This will be fixed for next release.

Kind Regards.