Add a "domfsinfo" command that shows a list of filesystems info mounted in
the guest. For example:

virsh # domfsinfo vm1
Mountpoint                           Name     Type     Target
-------------------------------------------------------------------
/                                    sda1     ext4     hdc
/opt                                 dm-2     vfat     vda,vdb
/mnt/test                            sdb1     xfs      sda
Signed-off-by: NTomoki Sekiyama <tomoki.sekiyama@hds.com>