[PATCH i-g-t v2] tests/kms_properties: Add skip on headless machines

[sumit kishore <sumit.kishore@intel.com>]

Print debug messages for sub-tests which are expected to
skip on headless display systems.

v2: Use existing library function, instead of
    defining new (karthik)

Signed-off-by: sumit kishore <sumit.kishore@intel.com>
---
 tests/kms_properties.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tests/kms_properties.c b/tests/kms_properties.c
index f735839da..9f5649c90 100644
--- a/tests/kms_properties.c
+++ b/tests/kms_properties.c
@@ -377,6 +377,8 @@ static void plane_properties(igt_display_t *display, bool atomic)
 	igt_output_t *output;
 	igt_crtc_t *crtc;
 
+	igt_display_require_output(display);
+
 	for_each_crtc_with_single_output(display, crtc, output) {
 		igt_display_reset(display);
 
@@ -400,6 +402,8 @@ static void crtc_properties(igt_display_t *display, bool atomic)
 	igt_crtc_t *crtc;
 	igt_output_t *output;
 
+	igt_display_require_output(display);
+
 	for_each_crtc_with_single_output(display, crtc, output) {
 		igt_display_reset(display);
 
-- 
2.43.0