staging: w35und: Remove unused spinlocks

This patch removes unused spinlocks from "struct mlme_frame" and "struct
wbsoft_priv".

Cc: Lars Lindley <lindley@coyote.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Ruslan Pisarev <ruslan@rpisarev.org.ua>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>