*: 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/appletlib.c b/libbb/appletlib.c
index 800c374..8daa233 100644
--- a/libbb/appletlib.c
+++ b/libbb/appletlib.c
@@ -7,9 +7,9 @@
  * here, please feel free to acknowledge your work.
  *
  * Based in part on code from sash, Copyright (c) 1999 by David I. Bell
- * Permission has been granted to redistribute this code under the GPL.
+ * Permission has been granted to redistribute this code under GPL.
  *
- * 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.
  */
 
 /* We are trying to not use printf, this benefits the case when selected