Fix WPS AP mode regression

Fix WPS AP mode regression

Commit 03d3f28a698ec2c269fed35b88be30373595eee2 broke initialization of
EAPOL authenticator state machines since an error value from
wpa_auth_sta_key_mgmt() (-1) was not handled properly and the fixed
wpa_key_mgmt_wpa_psk() identified the value as a PSK-based AKM because
of all bits being set to 1. The special error value needs to handled
separately to avoid skipping EAPOL state machine initialization.