Fernando Tatis Jr. has now allowed more home runs than he’s tallied. The slumping Padres outfielder’s miserable season continued Friday night when his error led to a Little League grand slam for the Cardinals’ JJ Wetherhold in San Diego’s 6-0 home loss. Tatis’ error turned what should have at most a two-run single into a single that cleared the bases and gave the Cardinals a 4-0 lead in the fifth inning. The two-time Gold-Glove winning right fielder simply whiffed while running forward, with