hostapd: fix AP mode initialization for nl80211

Always bring down the wlan interface, even when not changing the
BSSID, the interface also needs to be down for changing its type
from managed to AP mode.

src/drivers/driver_nl80211.c

@@ -4418,10 +4418,10 @@ static void *i802_init(struct hostapd_data *hapd,
 	/* start listening for EAPOL on the default AP interface */
 	add_ifidx(drv, drv->ifindex);
 
-	if (params->bssid) {
-		if (hostapd_set_iface_flags(drv, drv->ifname, 0))
-			goto failed;
+	if (hostapd_set_iface_flags(drv, drv->ifname, 0))
+		goto failed;
 
+	if (params->bssid) {
 		if (set_ifhwaddr(drv, drv->ifname, params->bssid))
 			goto failed;
 	}