Some would say patch it, and some would say leave it alone. A patch might get worked out with removal and re-inserting the stem. Left as is, it would probably not crack or chip some more, but there's no guarantee. I'd smoke it as-is and only consider pipe repair (yours or a pro's) if it shows signs of cracking or chipping more. A pro might glue in a slip of briar and then work it down even with the airway.