SEATTLE —And suddenly there were just two. In the space of a few hours Thursday, half of the four remaining NFL head coach openings were filled — one by a former longtime Seahawks assistant and another by a coach Seattle hoped to interview. The hirings of former Seahawks assistant Dave Canales by Carolina and Rams defensive coordinator Raheem Morris by Atlanta left only the Seahawks and the Washington Commanders with head coach openings. Morris’ hiring in Atlanta also depleted by one the number of known candidates for the Seahawks as they search for a successor to Pete Carroll. Morris was in A…