GPU/OpenGL: Fix possible error on shutdown

src/core/gpu_hw_opengl.cpp

@@ -25,6 +25,10 @@ GPU_HW_OpenGL::~GPU_HW_OpenGL()
     m_host_display->ClearDisplayTexture();
     ResetGraphicsAPIState();
   }
+
+  // One of our programs might've been bound.
+  GL::Program::ResetLastProgram();
+  glUseProgram(0);
 }
 
 bool GPU_HW_OpenGL::Initialize(HostDisplay* host_display)