Change enforceObjectLockProtections() to return the fetched entry along
with any error. This allows callers to reuse the entry and avoid
duplicate filer lookups.
The entry is returned as (*filer_pb.Entry, error):
- Returns (entry, nil) on success
- Returns (nil, nil) if object doesn't exist (not an error for deletes)
- Returns (entry, err) if object is locked (entry still returned)
- Returns (nil, err) on lookup failure
chrislu
eb6a56b6c6