Blender Git Loki

Cleanup: Silence warnings

```
...gpu_texture.c(466,7): warning C4555: result of expression not used
...gpu_texture.c(559,7): warning C4555: result of expression not used
...gpu_texture.c:1205:72: warning: pointer targets in passing argument 4 of ?glGetTexLevelParameteriv? differ in signedness [-Wpointer-sign]
```