lsfd: add flags, [-lL], representing file lock/lease states to XMODE column

lsfd: add flags, [-lL], representing file lock/lease states to XMODE column

The flags hide the details of locking: methods for locking (including
lease), mandatory or advisory, and ranges. The flags can be used only
for distinguishing three states: not locked, read (or shared) locked,
or write (or exclusive) locked.

An example output:

  # ./lsfd -Q '(XMODE =~ "....[lL]")'
  COMMAND             PID   USER ASSOC XMODE TYPE SOURCE MNTID     INODE NAME
  abrtd              1854   root     7 rw--L  REG  tmpfs    27      3093 /run/abrt/abrtd.pid
  ...
  qemu-system-x86 2846033   qemu    11 rw--l  REG   dm-2  1313   5146111 /var/lib/libvirt/images/acn.qcow2

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