drm drm_fb_helper: destroy modes

drm_setup_crtcs allocated modes using drm_mode_duplicate. Free
them in drm_fb_helper_crtc_free.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index aada26f..77fec5a 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -430,8 +430,11 @@
 	for (i = 0; i < helper->connector_count; i++)
 		kfree(helper->connector_info[i]);
 	kfree(helper->connector_info);
-	for (i = 0; i < helper->crtc_count; i++)
+	for (i = 0; i < helper->crtc_count; i++) {
 		kfree(helper->crtc_info[i].mode_set.connectors);
+		if (helper->crtc_info[i].mode_set.mode)
+			drm_mode_destroy(helper->dev, helper->crtc_info[i].mode_set.mode);
+	}
 	kfree(helper->crtc_info);
 }