lsfd: use extra information loaded from /proc/net/tcp6

lsfd: use extra information loaded from /proc/net/tcp6

Example output:

  # ./lsfd -Q '(TYPE == "TCPv6") and ((COMMAND == "sshd") or (COMMAND == "test_mkfds"))'
  COMMAND       PID USER ASSOC MODE  TYPE SOURCE MNTID   INODE NAME
  sshd         1137 root     4  rw- TCPv6 sockfs     9   34689 state=listen laddr=[::]:22
  test_mkfds 716926  jet     3  rw- TCPv6 sockfs     9 6042073 state=listen laddr=[::1]:12345
  test_mkfds 716926  jet     4  rw- TCPv6 sockfs     9 6042074 state=established laddr=[::1]:23456 raddr=[::1]:12345
  test_mkfds 716926  jet     5  rw- TCPv6 sockfs     9 6042075 state=established laddr=[::1]:12345 raddr=[::1]:23456

Signed-off-by: Masatake YAMATO <yamato@redhat.com>