ogc: flush the FIFO after executing the command queue

It can happens that the client program immediately calls
SDL_DestroyTexture() after draawing it. Luckily for us, SDL is smart
enough to realize that the texture has been used in a draw operation and
issues a SDL_RenderFlush() so that all the operations get executed. But
this means that on our side, we must also make sure that when we return
from OGC_RunCommandQueue() the texture data is no longer needed. The
call to GX_DrawDone() does exactly this.

Author: mardy

src/render/ogc/SDL_render_ogc.c

@@ -533,6 +533,7 @@ static int OGC_RunCommandQueue(SDL_Renderer *renderer, SDL_RenderCommand *cmd, v
         cmd = cmd->next;
     }
 
+    GX_DrawDone();
     return 0;
 }