drm/radeon/kms: properly handle mode id with native mode changes

drm modes are objects with indentifiers.  Make sure to preserve
the mode id when copying mode params.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c b/drivers/gpu/drm/radeon/radeon_connectors.c
index 17d5659..729207a 100644
--- a/drivers/gpu/drm/radeon/radeon_connectors.c
+++ b/drivers/gpu/drm/radeon/radeon_connectors.c
@@ -183,8 +183,7 @@
 	if (native_mode->hdisplay != 0 &&
 	    native_mode->vdisplay != 0 &&
 	    native_mode->clock != 0) {
-		mode = drm_mode_create(dev);
-		*mode = *native_mode;
+		mode = drm_mode_duplicate(dev, native_mode);
 		mode->type = DRM_MODE_TYPE_PREFERRED | DRM_MODE_TYPE_DRIVER;
 		drm_mode_set_name(mode);