When you’re making a movie about a British Pakistani Muslim rapper, it’s always a nice plus when you can actually hire a British Pakistani Muslim rapper. That’s what American documentarian turned feature-length filmmaker Bassam Tariq (“These Birds Walk”) did for “Mogul Mowgli,” a new drama starring actor/rapper Riz Ahmed (“Rogue One: A Star Wars Story,” “Nightcrawler“). In “Mogul Mowgli,” Ahmed plays British-Pakistani rapper Zed, a fierce MC on the cusp of a major tour and commercial success who returns to England on a family visit, only to be hospitalized with an autoimmune condition.