rrs_upgrade_history: improve checkout logic

* Consolidate the code for checking out a repository, using the newly
  added utils.checkout_repo() function
* Check out a layer's dependencies, not just the layer itself
* Only check out if the desired revision isn't already checked out
  (mostly useful for bitbake which we would otherwise be checking out
  much more frequently than necessary since it may not have changed
  even if we've moved to a new commit in the layer).

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>

0 files changed, 0 insertions, 0 deletions