LONDON (Reuters) – Britain’s advertising regulator has banned five adverts for Tesco’s mobile phone business, saying its use of the words “shiitake” and “pistachio” alluded to expletives and were offensive. The Advertising Standards Authority (ASA) said on Wednesday three of the ads were also banned because they were inappropriate for display where they could be seen by children. The watchdog said one full-page newspaper ad for Tesco Mobile in the Daily Express and in the Daily Mail featured text which stated: “What a load of shiitake” in large text, followed by an image of a mushroom. Underne…