drm: flip-work: change drm_flip_work_init prototype

Now that we're using lists instead of kfifo to store drm flip-work tasks
we do not need the size parameter passed to drm_flip_work_init function
anymore.
Moreover this function cannot fail anymore, we can thus remove the return
code.

Modify drm_flip_work_init users to take account of these changes.

[airlied: fixed two unused variable warnings]

Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/tilcdc/tilcdc_crtc.c

@@ -665,12 +665,8 @@ struct drm_crtc *tilcdc_crtc_create(struct drm_device *dev)
 	tilcdc_crtc->dpms = DRM_MODE_DPMS_OFF;
 	init_waitqueue_head(&tilcdc_crtc->frame_done_wq);
 
-	ret = drm_flip_work_init(&tilcdc_crtc->unref_work, 16,
+	drm_flip_work_init(&tilcdc_crtc->unref_work,
 			"unref", unref_worker);
-	if (ret) {
-		dev_err(dev->dev, "could not allocate unref FIFO\n");
-		goto fail;
-	}
 
 	ret = drm_crtc_init(dev, crtc, &tilcdc_crtc_funcs);
 	if (ret < 0)