drm/rockchip: Use for_each_oldnew_plane_in_state in vop_crtc_atomic_flush

for_each_obj_in_state is about to be removed, so use the new atomic
iterator macros.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Mark Yao <mark.yao@rock-chips.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-rockchip@lists.infradead.org
Link: http://patchwork.freedesktop.org/patch/msgid/20170712081344.25495-10-maarten.lankhorst@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Mark Yao <mark.yao@rock-chips.com>

drivers/gpu/drm/rockchip/rockchip_drm_vop.c

@@ -1029,7 +1029,7 @@ static void vop_crtc_atomic_flush(struct drm_crtc *crtc,
 				  struct drm_crtc_state *old_crtc_state)
 {
 	struct drm_atomic_state *old_state = old_crtc_state->state;
-	struct drm_plane_state *old_plane_state;
+	struct drm_plane_state *old_plane_state, *new_plane_state;
 	struct vop *vop = to_vop(crtc);
 	struct drm_plane *plane;
 	int i;
@@ -1060,11 +1060,12 @@ static void vop_crtc_atomic_flush(struct drm_crtc *crtc,
 	}
 	spin_unlock_irq(&crtc->dev->event_lock);
 
-	for_each_plane_in_state(old_state, plane, old_plane_state, i) {
+	for_each_oldnew_plane_in_state(old_state, plane, old_plane_state,
+				       new_plane_state, i) {
 		if (!old_plane_state->fb)
 			continue;
 
-		if (old_plane_state->fb == plane->state->fb)
+		if (old_plane_state->fb == new_plane_state->fb)
 			continue;
 
 		drm_framebuffer_reference(old_plane_state->fb);