Fix forgotten license comments

diff --git a/selinux/runcon.c b/selinux/runcon.c
index a9471ef..e94ff14 100644
--- a/selinux/runcon.c
+++ b/selinux/runcon.c
@@ -25,6 +25,8 @@
  *
  * Port to busybox: KaiGai Kohei <kaigai@kaigai.gr.jp>
  *                  - based on coreutils-5.97 (in Fedora Core 6)
+ *
+ * Licensed under GPLv2, see file LICENSE in this tarball for details.
  */
 #include <getopt.h>
 #include <selinux/context.h>