Do not print command invocation if QUIET

Makefile

@@ -37,7 +37,7 @@ test: test_format test_dirs test_files test_seek test_truncate test_parallel \
 	test_alloc test_paths test_orphan test_move test_corrupt
 test_%: tests/test_%.sh
 ifdef QUIET
-	./$< | sed -n '/^[-=]/p'
+	@./$< | sed -n '/^[-=]/p'
 else
 	./$<
 endif