Well that all depends on what mark it is?
The picture you attached shows nothing so it's pretty hard to gauge what mark it is?
My 15-22 bolt has a mark (on the side you can see when the bolt is closed) that looks like this < - - just above the extractor, it could just be a scratch, but it looks like an arrow and two lines. It does not impede the bolt any and is just on the surface so it doesn't effect the integrity of the bolt.
Without actually seeing the 'mark' on the bolt, I cannot tell ya.
However there is only one way to find out....Buy a brick of ammo and blast it all in as fast a time as possible...if the rifle sets on fire and then explodes, then you may have a problem, otherwise it could just be a manufacturing scratch and i would not worry about it.
A clearer picture of the mark could help us determine if you could have a problem or not.