wlantest: Distinguish EAPOL-Key msg 4/4 from 2/4 based on Key Nonce

wlantest: Distinguish EAPOL-Key msg 4/4 from 2/4 based on Key Nonce

IEEE P802.11be adds the MAC Address KDE into the EAPOL-Key msg 4/4 when
MLO is used and as such, the previously used check for Key Data Length
value 0 is not sufficient for recognizing the EAPOL-Key msg 4/4 anymore.
Also check for an all zero Key Nonce value since that field is supposed
to be zero in EAPOL-Key msg 4/4 and it has to be a random value in
EAPOL-Key msg 2/4.

Signed-off-by: Jouni Malinen <quic_jouni@quicinc.com>