It's able to close someone else's code review. All code review requests are in fact a TFS work item. You can close them in bulk by bulk updating them using Excel, just as you would do for any other work item.
- Create a work query to get all that user’s Code Review Request work
items which in Requested state
- Save this work item query and open this query in Excel, then edit
them work items in Excel to change the state to Closed,
- Then click Publish button to publish the updates to TFS Server.
The way to do is to open your code reviews query from the link on the
top right of Code Reviews section in Team Explorer

Once you are in query mode, click on "Save query" to save your code
review query. Now click on the "Open query in Excel" button

This would open up an excel sheet for you. Change the State of each of
code review work item that you would like to update. Then click on the
the Team menu and use the "Publish" button to make your changes in
TFS.

More details please refer this thread: Close someone else's code review TFS 2015
You could not restrict the user who created the code review to close code review. However, you could enforce Code Review before check-in time by using check-in policy. Once the code review failed, the user could not be able to check in his code. You could either write your own custom check-in policy or directly use 3-rd extensions--Colin's ALM Checkin Policies VS 2017.