As inet dgram sockets (udp, raw) can call connect(...)  - they
might be set in ESTABLISHED state. So keep the original behaviour of
'ss' which filtered them by ESTABLISHED state by default. So:

    $ ss -u

    or

    $ ss -w

Will show only ESTABLISHED UDP sockets by default.
Signed-off-by: Vadim Kochan <vadim4j@gmail.com>