MIAMI GARDENS — You wonder what will motivate the Miami Dolphins (6-8) in Sunday’s game against San Francisco 49ers (6-8) at Hard Rock Stadium. The season, from where things stand now, will likely be judged as a disappointment, at best, and there’s a good chance it’ll be determined to be a disaster. Defensive coordinator Anthony Weaver didn’t have any problems rattling off reasons the Dolphins should be motivated for their last three regular-season games — against San Francisco, at Cleveland and at the New York Jets. “This is our last home game, and our fans deserve our best effort,” Weaver began.