lsfd: show extra information returned from ioctl(..., NS_GET_NSTYPE)

lsfd: show extra information returned from ioctl(..., NS_GET_NSTYPE)

lsfd uses the information to fill the newly added NS.TYPE and NS.NAME
columns:

  # ./lsfd -oCOMMAND,PID,USER,ASSOC,SOURCE,MNTID,NS.TYPE,NS.NAME,NAME
           -Q '(FD >= 0) and (SOURCE == "nsfs")'
  COMMAND            PID USER ASSOC SOURCE MNTID NS.TYPE          NS.NAME NAME
  NetworkManager    1114 root     8   nsfs     3     net net:[4026531840] net:[4026531840]
  NetworkManager    1114 root     9   nsfs     3     mnt mnt:[4026532758] mnt:[4026532758]
  lsfd             14379 root     3   nsfs     3     net net:[4026531840] net:[4026531840]
  podman         1532759 root     7   nsfs  1546     net net:[4026533029] /run/netns/netns-4f5ecc46-d6a0-175c-46a8-2e4ba180b94a

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