fixes in Game.java Method gamePhase

src/main/java/ch/zhaw/pm2/racetrack/Game.java

@@ -179,17 +179,17 @@ public class Game implements GameSpecification {
     }
 
     public int gamePhase() throws PositionVectorNotValid {
-        do{
+        while (getWinner() == NO_WINNER) {
             userInterface.printTrack(track);
             Direction direction = track.getCar(currentCarIndex).getMoveStrategy().nextMove();
             doCarTurn(direction);
             int winner = getWinner();
-            if(winner != NO_WINNER) {
-                return winner;
+            if(allCarsCrashed()) {
+                return NO_WINNER;
             }
             switchToNextActiveCar();
-        } while (!allCarsCrashed());
-        return NO_WINNER;
+        }
+        return getWinner();
     }
 
     /**