As was said in your other topic, avast can't restore to the C: System Volume information folder as it is part of the system restore function.
That said the Restore function doesn't remove the copy from the chest. Take the example here you try to restore a file from the chest, but for some reason it fails, if the copy in the chest was removed during this process you would have no backup copy.
So this is a safety measure for want of a better description, until you confirm (a physical check of the folder) that the file has been Restored to its original location, a copy remains in the chest until you manually delete it from the chest.
As I have mentioned on other occasions - Infected Restore Points:
There really is little benefit in chasing a detection in the system volume information folder. It is only there because it had previously been deleted or moved from the system folders and this is a back-up created by system restore.
- Worst case scenario it isn't infected and you delete it, you can't use that restore point in the future, not much of a loss and the older the restore point is the less of an issue it is.
- So if there is any suspicion about a restore point then it is best removed from the system volume information folder or it could bite you in the rear at some point in the future when you use system restore if it included that restore point.
So manually delete it from the chest.