In this specific question: Gigabit Ethernet switch unused RGMII/MII/RMII interface, the OP gave an answer to its own question within the question itself, as an edit. If it was a partial answer, I don't think this would be a problem. However, in this case, I feel like it could be considered as a full answer.
I don't think it is something we want, generally. It clutters the unanswered posts list, and may lead to post auto-deletion. This would be a pity for a post that actually has an answer.
What would be the action to take, here? I already tried putting a comment to let the OP fix the problem, but this user doesn't seem very active, so I'm not sure it will have an effect.
Can the diamond mods convert the edit into an actual answer on behalf of OP? In the future, shall I flag for moderator attention, then? Or bring the case to meta?
If it is not possible to convert an edit to an answer, what can be done?
Maybe just forget about it and move on?