TALLADEGA, Ala. — Joey Logano used a controversial finish at Talladega Superspeedway to sweep the second round of NASCAR’s playoffs and end Dale Earnhardt Jr.’s championship chances. The race ended under caution when reigning Sprint Cup champion Kevin Harvick stumbled on the final restart to trigger a multi-car accident in the middle of the field. Because NASCAR said this week it would make just one attempt to finish the race under the green flag, the field was frozen and Earnhardt was denied the chance to race Logano for the win.