esp32: print mDNS status on the serial console

Make it easier to try to track down mDNS issues...

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

esp32/max80/wifi.cpp

@@ -199,6 +199,7 @@ static void mdns_setup(void)
 	{ NULL, NULL, 0 }
     };
     char unique_name[32];
+    esp_err_t unique_mdns;
 
     if (mdns_started)
 	mdns_free();
@@ -212,21 +213,21 @@ static void mdns_setup(void)
 
     mdns_hostname_set(hostname);
     mdns_instance_name_set(hostname);
+    printf("[MDNS] mDNS hostname set: %s\n", hostname);
 
-    unique_name[0] = 0;
-
+    unique_mdns = ESP_ERR_INVALID_STATE;
+    snprintf(unique_name, sizeof unique_name, "MAX80-%s", serial_number);
     if (connected & CON_STA) {
 	mdns_ip_addr_t iplist;
-
 	iplist.addr = ipaddr_toesp(WiFi.localIP());
 	iplist.next = NULL;
-	snprintf(unique_name, sizeof unique_name, "MAX80-%s", serial_number);
-	mdns_delegate_hostname_add(unique_name, &iplist);
+	unique_mdns = mdns_delegate_hostname_add(unique_name, &iplist);
+	printf("[MDNS] mDNS relegated unique hostname: %s\n", unique_name);
     }
 
     for (const struct mdns_service *svc = mdns_services; svc->type; svc++) {
 	mdns_service_add(NULL, svc->type, svc->proto, svc->port, NULL, 0);
-	if (unique_name[0]) {
+	if (unique_mdns == ESP_OK) {
 	    mdns_service_add_for_host(NULL, svc->type, svc->proto,
 				      unique_name, svc->port, NULL, 0);
 	}