better comment wording

[king6cong]

No description provided.

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @nikomatsakis (or someone else) soon.

If any changes to this PR are deemed necessary, please add them as extra commits. This ensures that the reviewer can see what has changed since they last reviewed the code. Due to the way GitHub handles out-of-date commits, this should also make it reasonably obvious what issues have or haven't been addressed. Large or tricky changes may require several passes of review and changes.

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[frewsxcv]

Thanks for the typo fixes!

@bors r+ rollup

[bors]

📌 Commit d59a2af has been approved by frewsxcv

[bors]

⌛ Testing commit d59a2af with merge 3f261ec...

[bors]

☀️ Test successful - status-appveyor, status-travis
Approved by: frewsxcv
Pushing 3f261ec to master...