staging: rtl8192e: rtl8192e: Remove create_workqueue()

With conccurency managed workqueues, use of dedicated workqueues can
be replaced by system_wq. Drop priv_wq by using system_wq.

Since there are multiple work items per priv but they do not need
to be ordered, increase of concurrency by switching to system_wq
should not break anything.

All work items are sync canceled on so it is guaranteed that
no work is running when rtl92e_suspend function is called.

Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>