lib/crc32: add SPDX license identifier

lib/crc32.c and include/linux/crc32.h got missed by the bulk SPDX
conversion because of the nonstandard explanation of the license.
However, crc32.c clearly states that it's licensed under the GNU General
Public License, Version 2.  And the comment in crc32.h clearly indicates
that it's meant to have the same license as crc32.c.  Therefore, apply
SPDX-License-Identifier: GPL-2.0-only to both files.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250514052409.194822-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>

Author: ebiggers

include/linux/crc32.h

@@ -1,7 +1,4 @@
-/*
- * crc32.h
- * See linux/lib/crc32.c for license and changes
- */
+/* SPDX-License-Identifier: GPL-2.0-only */
 #ifndef _LINUX_CRC32_H
 #define _LINUX_CRC32_H
 

lib/crc32.c

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Aug 8, 2011 Bob Pearson with help from Joakim Tjernlund and George Spelvin
  * cleaned up code to current version of sparse and added the slicing-by-8
@@ -19,9 +20,6 @@
  *   drivers/net/smc9194.c uses seed ~0, doesn't xor with ~0.
  *   fs/jffs2 uses seed 0, doesn't xor with ~0.
  *   fs/partitions/efi.c uses seed ~0, xor's with ~0.
- *
- * This source code is licensed under the GNU General Public License,
- * Version 2.  See the file COPYING for more details.
  */
 
 /* see: Documentation/staging/crc32.rst for a description of algorithms */