Update documentation for new_ret_no_self
Update documentation for new_ret_no_self

The lint was changed to be more lenient than the documentation implies in PR #3338.
Related issue #3313
aidancully/rust,graydon/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust