An interview is more about finding out whether you and the employer will be a good match for each other, than outlining technical facts. Yes, qualifications is one big part, but it most certainly is not the only part. Interviewers will generally want to find out what you are like as an individual and some amount of small talk is a good way to do that.
From what you have described, what was said basically amounts to some courtesy phrases at the beginning and the end of the conversation.
Consider this: if the interviewer considers something like that to be a negative, is the company likely to attract people that you would want to work with?
I think it's a fairly safe bet to say that if the employer will pass on you because you responded politely to their courtesy at the beginning and the end of the interview, the company is likely to attract mostly the kind of people who at least I would not want to work with. Hence, if they do look negatively on it, probably not a great loss.
Based on that line of reasoning, being reasonably polite during an interview can really only ever work in your favor, except possibly if you are truly desperate for a job, the interviewer is a jerk and you don't care about the work environment (and I'm not even sure about then).