Remove an useless condition in equal SEE pruning

Because we are never in check there and evaluation cannot
return a mated value the condition is useless.

No functional change.

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

src/search.cpp

@@ -1431,7 +1431,6 @@ split_point_start: // At split points actual search starts from here
           // Prune moves with negative or equal SEE
           if (   futilityBase < beta
               && depth < DEPTH_ZERO
-              && bestValue > value_mated_in(PLY_MAX)
               && pos.see(move) <= 0)
               continue;
       }