virsh.pod: Add zfs and vstorage pool types

Signed-off-by: NHan Han <hhan@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

tools/virsh.pod

@@ -4093,7 +4093,7 @@ I<--uuid> and I<--name>.
 You may also want to list pools with specified types using I<type>, the
 pool types must be separated by comma, e.g. --type dir,disk. The valid pool
 types include 'dir', 'fs', 'netfs', 'logical', 'disk', 'iscsi', 'scsi',
-'mpath', 'rbd', 'sheepdog' and 'gluster'.
+'mpath', 'rbd', 'sheepdog', 'gluster', 'zfs' and 'vstorage'.
 
 The I<--details> option instructs virsh to additionally
 display pool persistence and capacity related information where available.