drm/radeon: Add missing vblank_put in pageflip ioctl error path.

Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/radeon_display.c

@@ -538,7 +538,7 @@ static int radeon_crtc_page_flip(struct drm_crtc *crtc,
 		DRM_DEBUG_DRIVER("flip queue: crtc already busy\n");
 		spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
 		r = -EBUSY;
-		goto pflip_cleanup;
+		goto vblank_cleanup;
 	}
 	radeon_crtc->flip_status = RADEON_FLIP_PENDING;
 	radeon_crtc->flip_work = work;
@@ -551,6 +551,9 @@ static int radeon_crtc_page_flip(struct drm_crtc *crtc,
 	queue_work(radeon_crtc->flip_queue, &work->flip_work);
 	return 0;
 
+vblank_cleanup:
+	drm_vblank_put(crtc->dev, radeon_crtc->crtc_id);
+
 pflip_cleanup:
 	if (unlikely(radeon_bo_reserve(new_rbo, false) != 0)) {
 		DRM_ERROR("failed to reserve new rbo in error path\n");