ld: fix up header copy and paste error

Some constants were added above the initial copyright blurb, and then
later a new copyright blurb was added on top of that. So we wound up
with two header sections, one of which contained a useful comment that
became obscured. This commit fixes up that mistake.

Change-Id: I8b9b8c34495cdceae959e151e8ccdee3137f6ca4
Reviewed-on: https://go-review.googlesource.com/c/go/+/191841
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/cmd/link/internal/ld/pe.go

@@ -2,6 +2,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// PE (Portable Executable) file writing
+// https://www.microsoft.com/whdc/system/platform/firmware/PECOFF.mspx
+
 package ld
 
 import (
@@ -124,13 +127,6 @@ const (
 	IMAGE_REL_BASED_HIGHLOW = 3
 )
 
-// Copyright 2009 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// PE (Portable Executable) file writing
-// https://www.microsoft.com/whdc/system/platform/firmware/PECOFF.mspx
-
 // DOS stub that prints out
 // "This program cannot be run in DOS mode."
 var dosstub = []uint8{