Put the video prepare code back, and use the existence of the g_renderer to determine if video prepare has been run or not.

git-svn-id: https://dolphin-emu.googlecode.com/svn/trunk@7274 8ced0084-cf51-0410-be5f-012b33b47a6e

Source/Plugins/Plugin_VideoOGL/Src/GLUtil.cpp

@@ -529,15 +529,6 @@ bool OpenGL_MakeCurrent()
 	return true;
 }
 
-bool OpenGL_ReleaseContext()
-{
-#ifdef _WIN32
-	return wglMakeCurrent(NULL, NULL);
-#elif defined(HAVE_X11) && HAVE_X11
-	return glXMakeCurrent(GLWin.dpy, None, NULL);
-#endif
-}
-
 // Update window width, size and etc. Called from Render.cpp
 void OpenGL_Update()
 {