Make -yy output for inet sockets consistent with unix domain sockets

Make -yy output for inet sockets consistent with unix domain sockets

Prepend -yy output generated for INET/INET6 TCP/UDP sockets with their
protocol name obtained using getxattr.

* socketutils.c (inet_parse_response): Add proto_name argument.
Print proto_name for connected and unconnected sockets.
(receive_responses): Add proto_name argument, pass it to the parser.
(inet_print): Add proto_name argument, pass it to receive_responses.
(unix_parse_response): Add proto_name argument.
(print_sockaddr_by_inode): Pass protocol name to inet_print calls.
* tests/net-yy-accept.awk: Update to match new output format.
* tests/net-yy-connect.awk: Likewise.