Move the noatime check to a separate function (to be used by CL 91535),
adding some documentation along the way.
Unify the atime error message.
Change-Id: I5f75a4399f6e1b16ae20438003de5460f3eeb5aa
Reviewed-on: https://go-review.googlesource.com/c/go/+/594075 Reviewed-by: Ian Lance Taylor <iant@google.com> Reviewed-by: Joedian Reid <joedian@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>