tools lib traceevent: Update FSF postal address to be URL's.

The FSF now prefers to use URL's in copyright headers rather than
their postal address. This change updates the address to be
<http://www.gnu.org/licenses> per http://www.gnu.org/licenses/gpl-howto.html

Signed-off-by: Jon Stanley <jonstanley@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1347049967-3143-1-git-send-email-jonstanley@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>