Small codestyle touches

Mostly suggested by Justin (UncombedCoconut), the 0ULL -> 0 conversion
is mine.

No functional change.

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

src/movepick.h

@@ -66,7 +66,7 @@ private:
   int badCaptureThreshold, phase;
   const uint8_t* phasePtr;
   MoveStack *curMove, *lastMove, *lastGoodNonCapture, *badCaptures;
-  MoveStack moves[256];
+  MoveStack moves[MOVES_MAX];
 };