Made pistol grip controller work with the drivetrain.

Change-Id: Id5ede34e9a9981c338aaa6118eb5085578a8ecd3
diff --git a/y2016/joystick_reader.cc b/y2016/joystick_reader.cc
index 35477be..0cff7fb 100644
--- a/y2016/joystick_reader.cc
+++ b/y2016/joystick_reader.cc
@@ -159,7 +159,7 @@
       is_control_loop_driving = true;
     }
     if (!drivetrain_queue.goal.MakeWithBuilder()
-             .steering(wheel)
+             .wheel(wheel)
              .throttle(throttle)
              .highgear(is_high_gear_)
              .quickturn(data.IsPressed(kQuickTurn))