Baker Mayfield's Cockiness is a Good Thing, Says Browns Great Earnest Byner

[[tmz:video id="0_1qe6hl8k"]] Yeah, Baker Mayfield is cocky, but that's a great thing ... so says Browns legend Earnest Byner, who tells TMZ Sports the QB has the perfect mindset for bringing the franchise back to relevance. FYI -- Byner knows…