staging: rtl8723bs: fix monitor netdev register/unregister

Due to the locking changes and callbacks happening inside
cfg80211, we need to use cfg80211 versions of the register
and unregister functions if called within cfg80211 methods,
otherwise deadlocks occur.

Fixes: a05829a7 ("cfg80211: avoid holding the RTNL when calling the driver")
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20210426212801.3d902cc9e6f4.Ie0b1e0c545920c61400a4b7d0f384ea61feb645a@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>