batman-adv: remove FSF address from GPL disclaimer

As suggested by checkpatch, remove all the references to the
FSF address since the kernel already has one reference in
its documentation.

In this way it is easier to update it in case of future
changes.

Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
diff --git a/net/batman-adv/main.h b/net/batman-adv/main.h
index 322dd73..9e76b6c 100644
--- a/net/batman-adv/main.h
+++ b/net/batman-adv/main.h
@@ -12,9 +12,7 @@
  * General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
- * 02110-1301, USA
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
 
 #ifndef _NET_BATMAN_ADV_MAIN_H_