5   SOCK state=listen path=test_mkfds-unix-stream-ns     listen    stream              1 test_mkfds-unix-stream-ns
ASSOC,STTYPE,NAME,SOCK.STATE,SOCK.TYPE,SOCK.LISTENING,UNIX.PATH: 0
the netns for the stream socket is extracted as expectedly
    5   SOCK state=listen path=@test_mkfds-unix-stream-ns     listen    stream              1 @test_mkfds-unix-stream-ns
ASSOC,STTYPE,NAME,SOCK.STATE,SOCK.TYPE,SOCK.LISTENING,UNIX.PATH: 0
the netns for the abstract stream socket is extracted as expectedly