*: 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>
diff --git a/testsuite/seq.tests b/testsuite/seq.tests
index 7a55374..1e1116c 100755
--- a/testsuite/seq.tests
+++ b/testsuite/seq.tests
@@ -2,7 +2,7 @@
 
 # SUSv3 compliant seq tests.
 # Copyright 2006 by Rob Landley <rob@landley.net>
-# Licensed under GPL v2, see file LICENSE for details.
+# Licensed under GPLv2, see file LICENSE in this source tree.
 
 # AUDIT: Full SUSv3 coverage (except internationalization).