Unless there's some new information that I'm not aware of, the whitehall in negril is not on any do not travel list in the US. They are reffering to a neighborhood in Kingston called Whitehall that is a particularly ****ty neighborhood (I had an office there for about a year).

But even there as a visitor in the day you'd probably be ok. Don't do stupid things you wouldn't do in America and you'll be fine for the most part. Visitors are largley immune to the many problems Jamaica has