find_ref_lock
ref = find_ref_lock(hdl, id);
ref = find_ref_lock(hdl, ctrl->cluster[0]->id);
return find_ref_lock(hdl, which | 1) ? 0 : -EINVAL;
struct v4l2_ctrl_ref *ref = find_ref_lock(hdl, id);
id != class_ctrl && find_ref_lock(hdl, class_ctrl) == NULL)
struct v4l2_ctrl_ref *find_ref_lock(struct v4l2_ctrl_handler *hdl, u32 id);
struct v4l2_ctrl_ref *ref = find_ref_lock(hdl, id);