staging: rtl8192e: Remove mutex from rtllib_softmac_free()

staging: rtl8192e: Remove mutex from rtllib_softmac_free()

The following commands use the mutex ieee->wx_mutex:
cancel_delayed_work_sync(&ieee->associate_retry_wq)
cancel_delayed_work_sync(&ieee->associate_procedure_wq)
cancel_work_sync(&ieee->wx_sync_scan_wq)
Therefore they cannot be canceled with ieee->wx_mutex locked. As the
work functions are executed time shifted during normal operation of the
driver, proper locking can only be done inside the functions.

Signed-off-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Link: https://lore.kernel.org/r/a5308876bd8fabcb5f8b25d14dbad2c1f68ce59f.1695582999.git.philipp.g.hortmann@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>