Cut is a cleaner & more performant api relative to SplitN(_, _, 2) added in go 1.18
Previously applied this refactoring to buildah:
https://github.com/containers/buildah/pull/5239
Signed-off-by: Philip Dubé <philip@peerdb.io>
Initially just supporting just rctl_get_racct for
(*Container).GetContainerStats.
[NO NEW TESTS NEEDED] we are not running any FreeBSD tests in CI
Signed-off-by: Doug Rabson <dfr@rabson.org>