*: make GNU licensing statement forms more regular

This change retains "or later" state! No licensing _changes_ here,
only form is adjusted (article, space between "GPL" and "v2" and so on).

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

coreutils/sort.c

@@ -6,7 +6,7 @@
  *
  * MAINTAINER: Rob Landley <rob@landley.net>
  *
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  *
  * See SuS3 sort standard at:
  * http://www.opengroup.org/onlinepubs/007904975/utilities/sort.html