I can't imagine that you would need a whole new ticket. I would imagine this kind of thing happens from time to time with online booking. It's just an extra letter, not a different name...
Can you call the airline and ask what to do? I would imagine your passport number is associated with the ticket and as long as those two match, you'll be good to go. I bet they can print you a new ticket confirmation and you won't have a hassle at the airport.