all: go fmt ./...

Make all our package sources use Go 1.17 gofmt format
(adding //go:build lines).

Not strictly necessary but will avoid spurious changes
as files are edited.

Part of //go:build change (#41184).
See https://golang.org/design/draft-gobuild

Change-Id: I5b2b7d93424e828a3c5f76ae3f30ab825aca388e
Reviewed-on: https://go-review.googlesource.com/c/net/+/294371
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/internal/socket/cmsghdr_stub.go b/internal/socket/cmsghdr_stub.go
index 83c35ec..1d9f2ed 100644
--- a/internal/socket/cmsghdr_stub.go
+++ b/internal/socket/cmsghdr_stub.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !aix && !darwin && !dragonfly && !freebsd && !linux && !netbsd && !openbsd && !solaris && !zos
 // +build !aix,!darwin,!dragonfly,!freebsd,!linux,!netbsd,!openbsd,!solaris,!zos
 
 package socket