treewide: add license header and enable haslicense linter

Change-Id: I873a8d4082d75e8f813d8a726a41187eea7a065e
Reviewed-on: https://review.monogon.dev/c/monogon/+/3825
Tested-by: Jenkins CI
Reviewed-by: Leopold Schabel <leo@monogon.tech>
diff --git a/osbase/efivarfs/boot.go b/osbase/efivarfs/boot.go
index 8fe1a55..41fa7ce 100644
--- a/osbase/efivarfs/boot.go
+++ b/osbase/efivarfs/boot.go
@@ -1,25 +1,5 @@
-// MIT License
-//
-// Copyright (c) 2021 Philippe Voinov (philippevoinov@gmail.com)
-// Copyright 2021 The Monogon Project Authors.
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in all
-// copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-// SOFTWARE.
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
 
 package efivarfs
 
diff --git a/osbase/efivarfs/boot_test.go b/osbase/efivarfs/boot_test.go
index 9abd8f9..741a1e6 100644
--- a/osbase/efivarfs/boot_test.go
+++ b/osbase/efivarfs/boot_test.go
@@ -1,3 +1,6 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
 package efivarfs
 
 import (
diff --git a/osbase/efivarfs/devicepath.go b/osbase/efivarfs/devicepath.go
index d06960c..ada393c 100644
--- a/osbase/efivarfs/devicepath.go
+++ b/osbase/efivarfs/devicepath.go
@@ -1,3 +1,6 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
 package efivarfs
 
 import (
diff --git a/osbase/efivarfs/devicepath_test.go b/osbase/efivarfs/devicepath_test.go
index ad81279..1e4d3bd 100644
--- a/osbase/efivarfs/devicepath_test.go
+++ b/osbase/efivarfs/devicepath_test.go
@@ -1,3 +1,6 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
 package efivarfs
 
 import (
diff --git a/osbase/efivarfs/efivarfs.go b/osbase/efivarfs/efivarfs.go
index ab6da26..f6c489b 100644
--- a/osbase/efivarfs/efivarfs.go
+++ b/osbase/efivarfs/efivarfs.go
@@ -1,18 +1,5 @@
-// Copyright 2020 The Monogon Project Authors.
-//
+// Copyright The Monogon Project Authors.
 // SPDX-License-Identifier: Apache-2.0
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
 
 // Package efivarfs provides functions to read and manipulate UEFI runtime
 // variables. It uses Linux's efivarfs [1] to access the variables and all
diff --git a/osbase/efivarfs/osindications.go b/osbase/efivarfs/osindications.go
index a112163..1c2effe 100644
--- a/osbase/efivarfs/osindications.go
+++ b/osbase/efivarfs/osindications.go
@@ -1,3 +1,6 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
 package efivarfs
 
 import (
diff --git a/osbase/efivarfs/variables.go b/osbase/efivarfs/variables.go
index fe59324..01ed9f9 100644
--- a/osbase/efivarfs/variables.go
+++ b/osbase/efivarfs/variables.go
@@ -1,3 +1,6 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
 package efivarfs
 
 import (