fixes a debug print

Author: Veijo Pesonen

components/wifi/esp8266-driver/ESP8266Interface.cpp

@@ -509,7 +509,7 @@ int ESP8266Interface::socket_send(void *handle, const void *data, unsigned size)
             && (status != NSAPI_ERROR_OK));
 
     if (status == NSAPI_ERROR_WOULD_BLOCK && socket->proto == NSAPI_TCP) {
-        debug("Enqueuing the event call");
+        tr_debug("ESP8266Interface::socket_send(): enqueuing the event call");
         _global_event_queue->call_in(100, callback(this, &ESP8266Interface::event));
     } else if (status == NSAPI_ERROR_WOULD_BLOCK && socket->proto == NSAPI_UDP) {
         status = NSAPI_ERROR_DEVICE_ERROR;