Dave Grohl allegedly hired a divorce lawyer before announcing he fathered a love child, sparking speculation his 21-year marriage could be coming to an end. The Foo Fighters rocker, 55, shocked the music world on Tuesday by revealing he has become a father for the fourth time, admitting to having an affair behind his wife’s back. Grohl, who shares three daughters with wife Jordyn Blum – Violet, 18, Harper, 15, and Ophelia, 10 – said in a statement confirming the child’s arrival he is doing everything he can to “regain their trust and earn their forgiveness”, but it appears he’s preparing for a…