Fix spline drawing for Metal Gear Solid Portable Ops

![screen00002](https://f.cloud.github.com/assets/3000282/1016396/d439bae4-0bf8-11e3-83d1-401461c5bda3.jpg)

Issue #3343 , https://github.com/hrydgard/ppsspp/issues/1884, https://github.com/hrydgard/ppsspp/issues/1202