The lens won't hit the sensor but the light rays hit the sensor at such as acute angle that the edges and corners of the image are smeared. Do you shoot enough film to justify keeping it? The ASPH version is a mighty sharp lens in a small package.
BTW, the comment regarding the lens being too close to the sensor may have related to the fact that these adapter companies seem to make most of them about 1/2 mm too short. So, the Leica M lenses with very accurate infinity stops focus beyond infinity at their stop. I find this annoying. The Voigtlander VM-E adapter is the solution and what I think is the best way to go. It provides close focusing with Leica M lenses as well as a way to set your infinity stop. I mark the point on the adapter and use (easily removable and re-usable) tape to hold it in place.