Fixes a "crash" when loading a save that has been stored during crafting.

Note sure if this is the cause of #9482, but it could very well be.

What happens is that `recipe::batch` is not initialized *at all*. It happens to be (in my case) a huge number, therefor an equally huge number of results is created and added to the player inventory.

If the result/byproduct (lard + cracklings in my case) is counted by charges, it would probably still work (but it will take some time), but if the result/byproduct is not counted by charges a very huge number of individual items is added to the inventory and that can easily break the game.

Btw. it seems that the save data does not contain the batch size, so it will revert to batch = 1 when loading, but that won't cause a crash (I assume).