MINNEAPOLIS—Minnesota Vikings safety Harrison Smith ripped off his helmet once the victory was finally secured, after a 29-point lead on the Pittsburgh Steelers late in the third quarter evaporated into yet another teeth-clenching finish. Smith looked exhausted and exasperated, hardly excited at all. These Vikings don’t make anything easy on themselves. Dalvin Cook rushed for 205 yards and two touchdowns in his faster-than-expected return from a shoulder injury, and the Vikings held on to beat the Steelers 36–28 by forcing an incomplete pass in the end zone on the final play Thursday night. Ben Roethlisberger’s throw to Pat Freiermuth was on target, but Smith smashed into the rookie tight end at just the right moment to dislodge the ball as Xavier Woods and Anthony Barr converged. That gave the Vikings (6–7) a critical victory after they flirted with an unforgivable loss. “It is frustrating having to come down to the …