is_revoked check all viable subtrees

An indentation error coupled with an early return lead to cases
where a subtree containing a pertinent revocation event was not
searched, and a revoked token would report as unrevoked.

Closes-bug: #1294292
Change-Id: If56ae64d8a30b461563ee8be002544117fb14215
Merge "is_revoked check all viable subtrees"