Small simplification to Position::see

Verified there are no hidden bugs and is
actually a speed optimization:

Fixed games at 15+0.05 TC
ELO: 1.72 +-2.9 (95%) LOS: 87.5%
Total: 20000 W: 3741 L: 3642 D: 12617

No functional change

src/position.cpp

@@ -1077,7 +1077,6 @@ int Position::see(Move m) const {
 
  // Add the new entry to the swap list
  swapList[slIndex] = -swapList[slIndex - 1] + PieceValue[MG][captured];
- ++slIndex;
 
  // Locate and remove the next least valuable attacker
  captured = min_attacker<PAWN>(byTypeBB, to, stmAttackers, occupied, attackers);
@@ -1086,10 +1085,9 @@ int Position::see(Move m) const {
 
  // Stop before processing a king capture
  if (captured == KING && stmAttackers)
- {
- swapList[slIndex++] = QueenValueMg * 16;
  break;
- }
+
+ ++slIndex;
 
  } while (stmAttackers);