workqueue: remove the declaration of copy_workqueue_attrs()

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>
1 file changed