“Saturday Night Live’s” British Invasion continues this week with Helen Mirren at the helm. Sadly, Dame Helen’s new film, “Arthur,” starring Russell Brand in the title role, isn’t receiving great reviews. The Post’s Michael O’Sullivan, who gave the film one star, says Mirren is “a brilliant actress for whom writer Peter Baynham hasn’t managed to find a single humorous thing to say.” Yeesh. Hopefully “SNL” will do a better job for this amazing actress. Watch Mirren’s “SNL” promo, with the Foo Fighters and Andy Samburg, below.