removed old license and fixed license header

src/lib.rs

@@ -1,7 +1,8 @@
-// Copyright (c) 2023 YAC
-// SPDX-License-Identifier: FSFAP
-
-/* Copying and distribution of this file, with or without modification, are
+/*
+ * Copyright (c) 2023 YAC
+ * SPDX-License-Identifier: FSFAP
+ *
+ * Copying and distribution of this file, with or without modification, are
  * permitted in any medium without royalty provided the copyright notice and
  * this notice are preserved.  This file is offered as-is, without any warranty.
  */