CA-35392: The snapshot parent links are not correctly updated on upgrade.
CA-35392: The snapshot parent links are not correctly updated on upgrade.

Also add some debugging information when the upgrade happens.

Signed-off-by: Thomas Gazagnaire <d17b540e4bd20a6d2c62b93674760725b3f75517@citrix.com>

simonjbeaumont/xcp-rrdd,koushikcgit/xcp-rrdd,djs55/xcp-rrdd,johnelse/xcp-rrdd,koushikcgit/xcp-rrdd,djs55/squeezed,sharady/xcp-networkd,djs55/xcp-networkd,koushikcgit/xcp-networkd,robhoes/squeezed,simonjbeaumont/xcp-rrdd,johnelse/xcp-rrdd,djs55/xcp-networkd,sharady/xcp-networkd,koushikcgit/xcp-networkd,djs55/xcp-rrdd,koushikcgit/xcp-rrdd