trivial: Add a tri-unfilled-fog test
diff --git a/progs/trivial/SConscript b/progs/trivial/SConscript
index 76826d9..d699e2b 100644
--- a/progs/trivial/SConscript
+++ b/progs/trivial/SConscript
@@ -103,6 +103,7 @@
 	'tri-tex',
 	'tri-tex-3d',
 	'tri-tri',
+	'tri-unfilled-fog',
 	'tri-unfilled-edgeflag',
 	'tri-unfilled-clip',
 	'tri-unfilled-smooth',