rules: MouseScroll: Round to zero for signed values

Rounding to negative infinity makes no sense for the purpose here. While
the current code path probably won't run into a mistaken scroll amount
as no rule component returns a floating point number, let's fix this as
my radar beeped too.

Signed-off-by: Rongrong <i@rong.moe>

lib/logitech_receiver/diversion.py

@@ -1232,7 +1232,7 @@ class MouseScroll(Action):
     def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         amounts = self.amounts
         if is_number(last_result):
-            amounts = [math.floor(last_result * a) for a in self.amounts]
+            amounts = [math.trunc(last_result * a) for a in self.amounts]
         if logger.isEnabledFor(logging.INFO):
             logger.info("MouseScroll action: %s %s %s", self.amounts, last_result, amounts)
         dx, dy = amounts