mesa: call glutDestroyWindow() on exit
diff --git a/progs/demos/tunnel2.c b/progs/demos/tunnel2.c
index 75a199a..f4171a8 100644
--- a/progs/demos/tunnel2.c
+++ b/progs/demos/tunnel2.c
@@ -205,6 +205,8 @@
 {
    switch (k) {
    case 27:
+      glutDestroyWindow(channel[0]);
+      glutDestroyWindow(channel[1]);
       exit(0);
       break;