Refactor: cib: Check if on-disk cib is corrupt in the separate on_disk_cib_corrupt() rather than in validate_on_disk_cib()
Merge pull request #455 from gao-yan/on-disk-cib-corrupt-2

Refactor: cib: Check if on-disk cib is corrupt in the separate on_disk_cib_corrupt() rather than in validate_on_disk_cib()