drm/i915: use helpers

Signed-off-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 927d247..8796eb1 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -11738,21 +11738,20 @@
 				struct drm_file *file)
 {
 	struct drm_i915_get_pipe_from_crtc_id *pipe_from_crtc_id = data;
-	struct drm_mode_object *drmmode_obj;
+	struct drm_crtc *drmmode_crtc;
 	struct intel_crtc *crtc;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
 		return -ENODEV;
 
-	drmmode_obj = drm_mode_object_find(dev, pipe_from_crtc_id->crtc_id,
-			DRM_MODE_OBJECT_CRTC);
+	drmmode_crtc = drm_crtc_find(dev, pipe_from_crtc_id->crtc_id);
 
-	if (!drmmode_obj) {
+	if (!drmmode_crtc) {
 		DRM_ERROR("no such CRTC id\n");
 		return -ENOENT;
 	}
 
-	crtc = to_intel_crtc(obj_to_crtc(drmmode_obj));
+	crtc = to_intel_crtc(drmmode_crtc);
 	pipe_from_crtc_id->pipe = crtc->pipe;
 
 	return 0;