Check for EVENT_ASSOC data to be present for AP mode operation

wpa_supplicant_event() is required to include the event data for AP mode
events. In theory, a non-AP mode event could be sent here from the
driver wrapper, so reject such event.

Signed-off-by: Jouni Malinen <j@w1.fi>

wpa_supplicant/events.c

@@ -1872,6 +1872,8 @@ static void wpa_supplicant_event_assoc(struct wpa_supplicant *wpa_s,
 
 #ifdef CONFIG_AP
 	if (wpa_s->ap_iface) {
+		if (!data)
+			return;
 		hostapd_notif_assoc(wpa_s->ap_iface->bss[0],
 				    data->assoc_info.addr,
 				    data->assoc_info.req_ies,