all: fix license header

Change-Id: Ied2d1b07b90891c916a877e39ec9cdf49ff6b0be
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/220347
Reviewed-by: Damien Neil <dneil@google.com>
diff --git a/internal/cmd/generate-protos/main.go b/internal/cmd/generate-protos/main.go
index e735f5f..652f236 100644
--- a/internal/cmd/generate-protos/main.go
+++ b/internal/cmd/generate-protos/main.go
@@ -100,7 +100,7 @@
 
 	generatedPreamble = []string{
 		"// Copyright 2019 The Go Authors. All rights reserved.",
-		"// Use of this source code is governed by a BSD-style.",
+		"// Use of this source code is governed by a BSD-style",
 		"// license that can be found in the LICENSE file.",
 		"",
 		"// Code generated by generate-protos. DO NOT EDIT.",
diff --git a/internal/cmd/generate-types/main.go b/internal/cmd/generate-types/main.go
index 81b210a..62e147a 100644
--- a/internal/cmd/generate-types/main.go
+++ b/internal/cmd/generate-types/main.go
@@ -206,7 +206,7 @@
 
 	s := strings.Join([]string{
 		"// Copyright 2018 The Go Authors. All rights reserved.",
-		"// Use of this source code is governed by a BSD-style.",
+		"// Use of this source code is governed by a BSD-style",
 		"// license that can be found in the LICENSE file.",
 		"",
 		"// Code generated by generate-types. DO NOT EDIT.",