I understand your concern.
Now, there are two types of criminal backgrounds. First, there is an "arrest based" background. This background, as you may imagine, only shows arrests. Next, there is a "conviction based" background. This only shows convictions in one's history.
Because you were not arrested, nor charged, this incident will not appear on either one of your backgrounds. It is, essentially, as if it never happened for criminal background checks. It will not show up on any future background search an employer may conduct. This is because you were not legally arrested, nor were you charged with any crime.
The civil restitution is a different topic, unrelated to the criminal side of the incident. The restitution demand is purely a monetary issue, which is allowed under the law. A retailer may make a civil demand of a theft scenario. If payment is not made, the retailer may, if they so choose to, sue you in civil court, NOT criminal court. However, if one pays the restitution, they will make the retailer happy, which is something that one should do in this situation so as not to "rock the boat" and risk any "change of heart" on the part of Walmart.
I hope this information has been helpful. If you have any follow up questions based on what I have provided, please feel free to ask and I would be happy to answer them.
If not, please remember to click ACCEPT and rate my assistance as that is the only way I can be credited for assisting you this afternoon. Your cooperation in this regard would be greatly appreciated!