*: 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/libbb/getopt32.c b/libbb/getopt32.c
index 8c87fe3..eb99800 100644
--- a/libbb/getopt32.c
+++ b/libbb/getopt32.c
@@ -4,7 +4,7 @@
  *
  * Copyright (C) 2003-2005  Vladimir Oleynik  <dzo@simtreas.ru>
  *
- * 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.
  */
 
 #include <getopt.h>