t/helper: merge test-example-decorate into test-tool

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/t/t9004-example.sh b/t/t9004-example.sh
index b28a028..7e8894a 100755
--- a/t/t9004-example.sh
+++ b/t/t9004-example.sh
@@ -4,7 +4,7 @@
 . ./test-lib.sh
 
 test_expect_success 'decorate' '
-	test-example-decorate
+	test-tool example-decorate
 '
 
 test_done