largefile: use `parentchange` during rollback

rollback is updating parent without touching the working copy. It should wrapped
in a `parentchange` context.

Differential Revision: https://phab.mercurial-scm.org/D11108

hgext/largefiles/overrides.py

@@ -1636,6 +1636,7 b' def overriderollback(orig, ui, repo, **o'
             repo.wvfs.unlinkpath(standin, ignoremissing=True)
 
         lfdirstate = lfutil.openlfdirstate(ui, repo)
+        with lfdirstate.parentchange():
         orphans = set(lfdirstate)
         lfiles = lfutil.listlfiles(repo)
         for file in lfiles: