CONCORD, N.C. — Christopher Bell was in a must-win situation entering Sunday. And thanks to some Roval chaos, he did just that. Chase Elliott was in cruise control for much of Stage 3, maintaining a four-second lead as the race stayed under green for the most it ever has in the history of the Roval at Charlotte Motor Speedway. But a sponsorship sign on the inside wall on Turn 7 that blew onto the track prompted a caution and a restart with six laps to go, and flung the race into chaos. Elliott, contending for the lead, got nudged by Tyler Reddick and spun out — paving the way for Kevin Harvick…