bool tagged = !(port->flags & BRVLAN_F_UNTAGGED);
bool pvid = (port->flags & BRVLAN_F_PVID);
- blobmsg_printf(b, "%s%s%s%s\n", port->ifname,
+ blobmsg_printf(b, NULL, "%s%s%s%s\n", port->ifname,
tagged || pvid ? ":" : "",
tagged ? "t" : "",
pvid ? "*" : "");