This pre-declaration was unneeded since a previous refactor patch
6ba94429c8e7 ("workqueue: Reorder sysfs code").
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
 
 EXPORT_SYMBOL_GPL(system_freezable_power_efficient_wq);
 
 static int worker_thread(void *__worker);
-static void copy_workqueue_attrs(struct workqueue_attrs *to,
-                                const struct workqueue_attrs *from);
 static void workqueue_sysfs_unregister(struct workqueue_struct *wq);
 
 #define CREATE_TRACE_POINTS