drm/atomic: Use new iterator macros in drm_atomic_helper_wait_for_flip_done

for_each_obj_in_state is about to be removed, so use the correct new
iterator macro.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: David Airlie <airlied@linux.ie>
Link: http://patchwork.freedesktop.org/patch/msgid/20170712081344.25495-5-maarten.lankhorst@linux.intel.com
[mlankhorst: Based on danvet's feedback, only apply first hunk and rename crtc_state variable to unused]
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/drm_atomic_helper.c

@@ -1266,11 +1266,11 @@ EXPORT_SYMBOL(drm_atomic_helper_wait_for_vblanks);
 void drm_atomic_helper_wait_for_flip_done(struct drm_device *dev,
 					  struct drm_atomic_state *old_state)
 {
-	struct drm_crtc_state *crtc_state;
+	struct drm_crtc_state *unused;
 	struct drm_crtc *crtc;
 	int i;
 
-	for_each_crtc_in_state(old_state, crtc, crtc_state, i) {
+	for_each_crtc_in_state(old_state, crtc, unused, i) {
 		struct drm_crtc_commit *commit = old_state->crtcs[i].commit;
 		int ret;