Prevent reinforcing/repairing of spare parts with themself.

Fixes #7455 - if the item to repair is one of the items used to repair it, cancel the action. This also prevent repairing plastic chunks and similar.

Btw. what happens to the rags seems to be this:

One selects a rag to be reinforced, the game changes the item to be reinforced. Than it consumes a rag (as a rag is needed to do this). The first item it finds is the reinforced rag. This one will do and it is removed from the inventory. Therefor the reinforced rag never shows up.