SEOUL (Reuters) – Samsung Electronics Co Ltd on Tuesday said fourth-quarter operating profit jumped 50 percent, matching its earlier guidance, as record earnings in its chips business masked the negative impact of its failed Note 7 phones. The world's biggest maker of smartphones and memory chips said October-December operating profit was 9.22 trillion won ($7.93 billion), compared with prior guidance of 9.2 trillion won. Revenue remained flat at 53.3 trillion won from the same period a year earlier, versus its estimate of 53 trillion won. Samsung also said it plans to buy back 9. …