Ever fewer pilots smoke these days - the risk to your licence as you get older is a serious disincentive! However, I'm fairly sure that it would be illegal to refuse to employ someone on the grounds of them being a smoker, unless health problems were already evident.
What you can't cater for are the prejudices of individual interviewers, who may be personally strongly anti-smoking and who could find fault with you elsewhere if you offend them by smelling strongly of cigarette smoke at interview.
Just as you would (I hope) take all precautions to avoid BO at your interview, try not to smell of smoke; to some it is just as offensive, and it is certainly avoidable. You can go without a cigarette for a couple of hours beforehand - can't you?
A final tip - chewing gum will not disguise the smell of cigarettes on your clothes, and some interviewers are as strongly anti gum as others are anti smoking! Don't give an interviewer a stick to beat you with...