update_vap_stats() fails for wlan0.0 in Gl.Inet B1300

[mariomaz]

PPM-311

Method beerocks::utils::get_iface_string_from_iface_vap_ids computes VAP name from interface name and VAP id using a hardcoded formula that produces names like "wlan0.0", "wlan0.1" and so on. While this is working fine for devices like RAX40, it does not work with Gl.Inet B1300, where there's only one VAP and it has the same name as the interface, so the computed VAP name does not exist.

To fix the problem, BSS (or name) of the VAP is now read from the device instead of computing it.