This verse you referenced has nothing to do with stoning (ie., punishment for adultery).
The confusion here is stemming from your understanding of "stones". The stones mentioned here are not just random stones such as the ones that are found on the ground [which tend to be used for the God-ordained punishment of stoning (eg, using a large rock/stone)].
The stones mentioned in the verse are referring to the stone idols which people made and worshiped [while it was nothing but a worthless statue with no power to benefit or help them]. These idols will be in Hell alongside these polytheists, fueling Hell. (And possibly, serving as a reminder to these polytheists as to why they are in Hell and that only Allah has power, not idols).
This is proven from another verse:
إنكم وما تعبدون من دون الله حصب جهنم أنتم لها واردون (Indeed, you [disbelievers] and what you worship other than Allah are the firewood of Hell. You will be coming to [enter] it) - Qur'an 21:98.
Hope this helps clear up the confusion. Thanks for asking.