I would think over time, the deer will venture to the new site. I guess you could cover it up with logs or old stumps, obviously deer aren't going to move them. Over time, the salt will seep deeper and deeper in the ground and it will no longer be as attractive to the deer. I would think in a year or two's time it'd be back to normal and they would have found the new site by then too. Place some whole-corn around the site as well if you think they aren't finding it soon enough- but my guess is that they will find it rather quickly. You could also place a trail cam at both spots and monitor which one they are frequenting more over the course of a year.