cmd/vet: add missing copyright header

Change-Id: I78942dde77547f91daebe763328f52b4c476ddaf
GitHub-Last-Rev: 423f1683fc
GitHub-Pull-Request: golang/go#47334
Reviewed-on: https://go-review.googlesource.com/c/go/+/336434
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Than McIntosh <thanm@google.com>

src/cmd/vet/main.go

@@ -1,3 +1,7 @@
+// Copyright 2012 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.
+
 package main
 
 import (

src/cmd/vet/testdata/copylock/copylock.go

@@ -1,3 +1,7 @@
+// Copyright 2018 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.
+
 package copylock
 
 import "sync"

src/cmd/vet/testdata/httpresponse/httpresponse.go

@@ -1,3 +1,7 @@
+// Copyright 2018 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.
+
 package httpresponse
 
 import (

src/cmd/vet/testdata/testingpkg/tests.go

@@ -1 +1,5 @@
+// Copyright 2018 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.
+
 package testdata

src/cmd/vet/testdata/testingpkg/tests_test.go

@@ -1,3 +1,7 @@
+// Copyright 2018 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.
+
 package testdata
 
 func Example_BadSuffix() {} // ERROR "Example_BadSuffix has malformed example suffix: BadSuffix"