internal/syscall/unix: fix UTIME_OMIT for dragonfly
CL 219638 added UTIME_OMIT values for various systems. The value for
DragonFly BSD appears to be incorrect.
The correct value is -2 (see references below), while -1 is used for
UTIME_NOW. As a result, timestamp is changed to the current time instead
of not touching. This should have been caught by the accompanying test
case, TestChtimesWithZeroTimes, but its failures are essentially skipped
on dragonfly (this is being fixed separately in a followup CL 591535).
Improve formatting while at it.
References:
- https://github.com/DragonFlyBSD/DragonFlyBSD/blob/
965b380e9609/sys/sys/stat.h#L284
- https://go.googlesource.com/sys/+/refs/tags/v0.20.0/unix/zerrors_dragonfly_amd64.go#1421
Change-Id: I432360ca982c84b7cd70d0cf01d860af9ff985fa
Reviewed-on: https://go-review.googlesource.com/c/go/+/589496
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Auto-Submit: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Commit-Queue: Ian Lance Taylor <iant@golang.org>