unix: follow convention for generated code comment

Follow the convertion (https://golang.org/s/generatedcode) for generated
code.

Change-Id: I27899b24366d5c0d2c5574b5eaf3d7e0babc8909
Reviewed-on: https://go-review.googlesource.com/118820
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/unix/zerrors_linux_arm64.go b/unix/zerrors_linux_arm64.go
index bb52191..8d70233 100644
--- a/unix/zerrors_linux_arm64.go
+++ b/unix/zerrors_linux_arm64.go
@@ -3,7 +3,7 @@
 
 // +build arm64,linux
 
-// Created by cgo -godefs - DO NOT EDIT
+// Code generated by cmd/cgo -godefs; DO NOT EDIT.
 // cgo -godefs -- -Wall -Werror -static -I/tmp/include -fsigned-char _const.go
 
 package unix