f2fs: add SPDX license identifiers

Remove the verbose license text from f2fs files and replace them with
SPDX tags.  This does not change the license of any of the code.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c
index 77a010e..7261245 100644
--- a/fs/f2fs/xattr.c
+++ b/fs/f2fs/xattr.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * fs/f2fs/xattr.c
  *
@@ -13,10 +14,6 @@
  *  suggestion of Luka Renko <luka.renko@hermes.si>.
  * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>,
  *  Red Hat Inc.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
  */
 #include <linux/rwsem.h>
 #include <linux/f2fs_fs.h>