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>
diff --git a/include/drm/drm_flip_work.h b/include/drm/drm_flip_work.h
index 3fcb4c4..d387cf0 100644
--- a/include/drm/drm_flip_work.h
+++ b/include/drm/drm_flip_work.h
@@ -85,7 +85,7 @@
 void drm_flip_work_queue(struct drm_flip_work *work, void *val);
 void drm_flip_work_commit(struct drm_flip_work *work,
 		struct workqueue_struct *wq);
-int drm_flip_work_init(struct drm_flip_work *work, int size,
+void drm_flip_work_init(struct drm_flip_work *work,
 		const char *name, drm_flip_func_t func);
 void drm_flip_work_cleanup(struct drm_flip_work *work);