maple_tree: update copyright dates for test code

Add the span to the year of the development.

Link: https://lkml.kernel.org/r/20221025173709.2718725-1-Liam.Howlett@oracle.comSigned-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

tools/testing/radix-tree/maple.c

 // SPDX-License-Identifier: GPL-2.0+
 /*
- * maple_tree.c: Userspace shim for maple tree test-suite
- * Copyright (c) 2018 Liam R. Howlett <Liam.Howlett@Oracle.com>
+ * maple_tree.c: Userspace testing for maple tree test-suite
+ * Copyright (c) 2018-2022 Oracle Corporation
+ * Author: Liam R. Howlett <Liam.Howlett@Oracle.com>
  *
  * Any tests that require internal knowledge of the tree or threads and other
  * difficult to handle in kernel tests.