Lady Gaga has revealed that she has quit smoking completely and went "cold turkey" on the habit.The singer told New Music Daily on Apple Music, "I swear on my life I’m not smoking cigarettes."Gaga detailed how "brutal" it was kicking the habit, but that she's not going back.Lady Gaga has just released her long-awaited new single, "Stupid Love," and she's also quit an unhealthy habit she once had.During an interview with New Music Daily with Zane Lowe on Apple Music, Lady Gaga said, "I’m not