Calluses are formed from blisters, which are in turn caused by repeated rubbing on a certain area of skin. Calluses are wonderful to have on, say, the bottom of your feet, or the palms of your hands. Would Wolverine's regenerative abilities allow him to form calluses? Or does this macho hero have soft, baby-like skin that prevents him from blistering?
Calluses are growths that the body makes in response to irritation by friction. The most well-known example is that of a guitarist's hand, or runners' feet. The guitarist strums and slides his fingers along the strings, which in turn slightly damages the skin. The same for the runner, as the friction from running rubs away at the skin.
To sum it all up, calluses are grown in response to injury, to prevent further damage, like scabs. They are not purely beneficial adaptive mutations. They can also be considered growths that come out of damaged tissue, like scar tissue (which Wolverine is said not to form, except for psychological/neurological ones).
Because Wolverine's body can repair any damage innately, without the need for 'defensive' growths, it can be reasonably concluded that Wolverine would not form calluses. His body would recover faster than his body could recognize the need or potential for a callus, and his body can heal to much greater effect and would not need or even benefit from calluses unlike regular people (to prevent further damage on the skin that our bodies can't heal completely/efficiently).
There are also examples where Wolverine has been partially or mostly incinerated apart from his skeleton and has also regenerated without any defensive growths, even within minutes or seconds. Personally, Wolverine's healing ability is so great that I feel it should be looked at separate from regular humans almost entirely, but that's just me.