None. I wouldn't worry about it at all. It's rare for a realtor or an agent to take into account closings of firehouses when doing a market analysis on a home. The only time something like that would be of concern would be if you were located literally next to it or perhaps across from it, but even then the change would be minimal.
Usually home near the Fire station is less desirable for potential buyers, because everybody afraid of the possible noise and peace disturbance. So, the closing of Fire station will make homes near by more desirable and, we can expect higher offers for them, but on another hand: home closer to Fire station has a lower rate for home owners insurance.