fix hardcoded origin name in checkAdjustedClone

fix hardcoded origin name in checkAdjustedClone

init: Fix a crash when the repo's was cloned from a repo that had an
adjusted branch checked out, and the origin remote is not named "origin".

The only other hardcoding of the name of origin is in:

- Upgrade.V2, which can be ignored probably
- Annex.Branch, which doesn't fail if it has some other name, but just
  doesn't set up the git-annex branch with quite as linear a history in
  that case.