wifi: mac80211: fix crash in beacon protection for P2P-device

If beacon protection is active but the beacon cannot be
decrypted or is otherwise malformed, we call the cfg80211
API to report this to userspace, but that uses a netdev
pointer, which isn't present for P2P-Device. Fix this to
call it only conditionally to ensure cfg80211 won't crash
in the case of P2P-Device.

This fixes CVE-2022-42722.

Reported-by: Sönke Huster <shuster@seemoo.tu-darmstadt.de>
Fixes: 9eaf183af741 ("mac80211: Report beacon protection failures to user space")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
