Cavour wasn't interested in Italian unification, he was interested in furthering the goals of the Savoyards, and increasing his own fame and influence while he was at it. Much like Bismarck and Prussia, though not as lucky.
In regards to the OP Italy is divided between Savoyard north and Bourbon south. Now, with that being said, total Italian unification is unlikely to be completely stopped at such a late point. While Garibaldi becomes a martyr to the Italian unification, and republican, movements, he wasn't the only leader of those causes. Remember that the Expedition wouldn't have been so successful if the Neapolitans hadn't risen up against the Bourbon garrisons.