Look it’s your decision as a seller. I am quite surprised you are asking these questions.
Here is a copy of a section in Fiverr’s TOS:
-Revisions to deliveries can be performed by sellers based on the seller’s Gig and customer care. Sellers may determine the amount of revisions offered to buyers, including no revisions.
-Requests for revisions can be performed through the Order page while the order is marked as Delivered.
Completed orders may be cancelled, upon review of our Customer Support team, up to 14 days after the order is marked as complete.
An order is marked as complete after the order is marked as Delivered and then rated by a buyer. An order will be automatically marked as complete if not rated and no request for modification was submitted within 3 days after marked as Delivered.
If you don’t honor the revision, your buyer might leave negative feedback which potentially can hurt your sales further down the road. Which he might do anyways, if he doesn’t like the end result.
If you did your work according to the gig description incl. revisions you have offered, I would not cancel. You did the work and your buyer should be paying for your service.