staging: wfx: delayed_unjoin cannot happen

staging: wfx: delayed_unjoin cannot happen

Original code allows to detect an unjoin request during a scan and
delaying the unjoin request. However, it is far easier to just block the
unjoin request until the end of the scan request.

In fact, it is already the case since scan and unjoin are protected by
conf_mutex. So, currently, the handling of delayed_unjoin is just dead
code.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20191217161318.31402-53-Jerome.Pouiller@silabs.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>