Big trailing whitespace cleanup part 1

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

src/history.cpp

@@ -7,12 +7,12 @@
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
-  
+
   Stockfish is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
-  
+
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
@@ -92,7 +92,7 @@ int History::move_ordering_score(Piece p, Move m) const {
 
 
 /// History::ok_to_prune() decides whether a move has been sufficiently
-/// unsuccessful that it makes sense to prune it entirely. 
+/// unsuccessful that it makes sense to prune it entirely.
 
 bool History::ok_to_prune(Piece p, Move m, Depth d) const {
   assert(piece_is_ok(p));