largefile: use `update_file` instead of `drop` during `rollback`
This is the newer, more semantic API.
Differential Revision: https://phab.mercurial-scm.org/D11192
largefile: use `update_file` instead of `drop` in `synclfdirstate`
This is the newer, more semantic API.
Differential Revision: https://phab.mercurial-scm.org/D11191