demos: add some fflushes for windows
diff --git a/progs/demos/reflect.c b/progs/demos/reflect.c
index 0bec066..b72af12 100644
--- a/progs/demos/reflect.c
+++ b/progs/demos/reflect.c
@@ -401,6 +401,7 @@
          GLfloat seconds = (t - t0) / 1000.0;
          GLfloat fps = frames / seconds;
          printf("%d frames in %g seconds = %g FPS\n", frames, seconds, fps);
+         fflush(stdout);
          t0 = t;
          frames = 0;
       }