Update Comments in CylindricalPanel.js
Update Comments in CylindricalPanel.js

Summary:
Thanks for submitting a PR! Please read these instructions carefully:

- [x] Explain the **motivation** for making this change.
- [x] Provide a **test plan** demonstrating that the code is solid.
- [x] Match the **code formatting** of the rest of the codebase.

## Motivation (required)

Just doc typos

## Test Plan (required)

A good test plan has the exact commands you ran and their output, provides screenshots or videos if the pull request changes UI or updates the website. See [What is a Test Plan?][1] to learn more.

If you have added code that should be tested, add tests.

## Next Steps

Sign the [CLA][2], if you haven't already.

Small pull requests are much easier to review and more likely to get merged. Make sure the PR does only one thing, otherwise please split it.

Make sure all **tests pass** on [Circle CI][3]. PRs that break tests are unlikely to be merged.

For more info, see the ["Pull Requests"][4] section of our "Contributing" guidelines.

[1]: https://medium.com/martinkonicek/what-is-a-test-plan-8bfc840ec171#.y9lcuqqi9
[2]: https://code.facebook.com/cla
[3]: http://circleci.com/gh/facebook/react-native
[4]: https://github.com/facebook/react-vr/blob/master/CONTRIBUTING.md#pull-requests
Closes https://github.com/facebook/react-vr/pull/167

Reviewed By: amberroy

Differential Revision: D4976006

Pulled By: amberroy

fbshipit-source-id: fe58c41

ichengde/react-vr,ichengde/react-vr