*: 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/networking/telnetd.c b/networking/telnetd.c
index ea66a25..5c011e1 100644
--- a/networking/telnetd.c
+++ b/networking/telnetd.c
@@ -3,7 +3,7 @@
  * Simple telnet server
  * Bjorn Wesen, Axis Communications AB (bjornw@axis.com)
  *
- * 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.
  *
  * ---------------------------------------------------------------------------
  * (C) Copyright 2000, Axis Communications AB, LUND, SWEDEN