ReplicatedPG: Also count overlaps for snapsets on snapdirs
ReplicatedPG: Also count overlaps for snapsets on snapdirs

Previously, the overlaps for snapdirs would not be included in
cstat causing the computed total to be incorrect.

Signed-off-by: Samuel Just <4c46b94684b338bae1ed5e7e1321718dd75401cc@dreamhost.com>

ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph