SEATTLE — So much for controlling their own destiny. Needing only to win their final two games of the season to assure a playoff spot, the Seahawks turned in one of their worst defensive efforts of this or any recent year, allowing a Pittsburgh Steelers team that has been among the worst offensive teams in the NFL all season to run over them all day long and grab a 30-23 win Sunday at Lumen Field. With the defeat, Seattle fell to 8-8 and now will need to win next week at Arizona and get some help elsewhere to clinch a playoff spot. And with Minnesota and Green Bay playing Sunday night, that me…