fix netname6().  we need to do "domask()" equivalent, to print "netstat -i" correctly.
fix netname6().  we need to do "domask()" equivalent, to print "netstat -i"
correctly.

fixed
Name  Mtu   Network       Address              Ipkts Ierrs    Opkts Oerrs Colls
sm1   1500  <Link>        00:00:86:05:80:fa    35776     0    37740     0   101
sm1   1500  fe80:1::/64   fe80:1::200:86ff:fe05:80fa    35776     0    37740     0   101
sm1   1500  3ffe:507:0:1::/64 3ffe:507:0:1:200:86ff:fe05:80fa    35776     0    37740     0   101

wrong
Name  Mtu   Network       Address              Ipkts Ierrs    Opkts Oerrs Colls
sm1   1500  <Link>        00:00:86:05:80:fa    35780     0    37740     0   101
sm1   1500  fe80:1::200:86ff:fe05:80fa/64 fe80:1::200:86ff:fe05:80fa    35780     0    37740     0   101
sm1   1500  3ffe:507:0:1:200:86ff:fe05:80fa/64 3ffe:507:0:1:200:86ff:fe05:80fa    35780     0    37740     0   101

MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame