ffplay: free subtitle pictures on exit

Signed-off-by: Marton Balint <cus@passwd.hu>

ffplay.c

@@ -1018,6 +1018,8 @@ static void stream_close(VideoState *is)
             vp->bmp = NULL;
         }
     }
+    for (i = 0; i < SUBPICTURE_QUEUE_SIZE; i++)
+        free_subpicture(&is->subpq[i]);
     SDL_DestroyMutex(is->pictq_mutex);
     SDL_DestroyCond(is->pictq_cond);
     SDL_DestroyMutex(is->subpq_mutex);