Probably warts. If you are processing it yourself, see if the sores are only hide deep or if they penetrate down into the meat. If they appear infected and produce yellowish pus it is generally recommended not to eat it. Looking at the pictures in my opinion it doesn't look like much to worry about. I'd be interested in seeing what it looks like underneath. Deer get warts, tumors, skin tags, insect bites etc and most of the time it's nothing to worry about.