Linter complains when using arrow function for refs

Created by: mrscobbler

I'm using arrow function for refs as explained in the docs here: https://facebook.github.io/react/docs/more-about-refs.html

but the linter complains with this:

217:54 warning Arrow function should not return assignment

Is there an issue with the way the docs describe how to use arrow functions with refs? Should the docs be updated?