v1.2.5a <-> v1.2.6 Volume mismatch

[commonism]

as discussed here DMTF/Redfish-Tools#474

Volume 1.10.0 in v1.2.5a mismatches the definition in v1.2.6
The schema was changed without creating a new revision.

[rahlvers]

Will address in the "SNIA Standard" release of 1.2.7.