method AddrInfo#inspect_sockaddr.
(inspect_sockaddr): extracted from addrinfo_inspect.
(addrinfo_inspect): use inspect_sockaddr.
(Init_addrinfo): define the new method.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@21648 b2dd03c8-39d4-4d8f-98ff-823fe69b080e