I don't think he would be "pushed to the front of the line" just because he is a celeb. There is the matter of matching the donor organ to the recipient, for one thing: when an organ becomes available, it is quickly entered into a computer database that generates a list of potential recipients, based on objective criteria - blood and tissue types, size of the organ, medical urgency of the patient, time on the waiting list, and distance between donor and recipient. Each organ has its own specific criteria.
Ethnicity, gender, religion, addictions, fame and fortune are not factors in that database.
The surgeon who will perform the transplant is notified and will decide whether to accept the donation, based upon the current health of the recipient. This is where age or pre-existing conditions may determine the outcome.
It is actually the donor who is usually screened for medical and social histories, so that is where a history of drug or alcohol abuse is usually noted and is considered a negative for donation.
Most of us "ruin our bodies" in ways small or large - who is to say who is worthy? I certainly wouldn't want to be the judge of that ...