Several files refer to an old address for the Free Software Foundation
in the file header comment.  Resolve by replacing the address with
the URL <http://www.gnu.org/licenses/> so that we do not have to keep
updating the header comments anytime the address changes.

CC: netfilter@vger.kernel.org
CC: Pablo Neira Ayuso <pablo@netfilter.org>
CC: Patrick McHardy <kaber@trash.net>
CC: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>