After whiffing big with its previous two earnings reports, Fortinet Inc. delivered upbeat profit and billings numbers for the latest quarter Tuesday, helping to send its stock rocketing. The cybersecurity company generated fourth-quarter net income of $310.9 million, or 40 cents a share, which was nearly flat from the$313.8 million, or 40 cents a share, that Fortinet FTNT, +2.10% logged a year before. On an adjusted basis, the company earned 51 cents a share, while analysts tracked by FactSet were modeling ...