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/ipv4/defs_openbsd.go b/ipv4/defs_openbsd.go
index 8f8af1b..cfde236 100644
--- a/ipv4/defs_openbsd.go
+++ b/ipv4/defs_openbsd.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 ignore
 // +build ignore
 
 // +godefs map struct_in_addr [4]byte /* in_addr */