Update Copyright

Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
diff --git a/squashfs-tools/xattr.h b/squashfs-tools/xattr.h
index 1762f06..003d0e4 100644
--- a/squashfs-tools/xattr.h
+++ b/squashfs-tools/xattr.h
@@ -2,7 +2,7 @@
  * Create a squashfs filesystem.  This is a highly compressed read only
  * filesystem.
  *
- * Copyright (c) 2010, 2012
+ * Copyright (c) 2010, 2012, 2013
  * Phillip Lougher <phillip@squashfs.org.uk>
  *
  * This program is free software; you can redistribute it and/or