Adoption specification change from review feedback
Adoption specification change from review feedback

Reviewers pointed out that the ADOPTION_FAILED state is inconsistent
with the other states and the original state machine specification.

As such, changing the ADOPTION_FAILED state name to ADOPTFAIL.

Partial-Bug: #1526315
Change-Id: If8095a4268556857f1bd3071c0ad198a3410501a

openstack/ironic-specs,NaohiroTamura/ironic-specs,bcornec/ironic-specs