NEW YORK — Losers no more. The Knicks bounced back on Friday night in their 121-112 win over the Detroit Pistons to get back to .500 with a 6-6 record. RJ Barrett turned in arguably his best performance of the season. The 22-year-old racked up 30 points on 10-of-17 shooting from the field with five rebounds and five assists. Barrett snapped the Knicks’ streak of poor shooting late in the first quarter as they started 0 for 7 from downtown as he dished a corner pass to Immanuel Quickley who delivered the dagger with under a minute to go and seal the victory for the Knicks. The Pistons made a la…