Optimisation: inline css <style> in modules/stats.php

#### Steps to reproduce the issue
Looking on home page code, I saw this #wpadminbar .quicklinks css not inline. Simple easy fast update. It's always showing up on my performances scans so I just want to let you guys know that it is not a big deal but would be a tiny improvement. It is located in the file jetpack/modules/stats.php.

#### What I expected
<style type='text/css'>#wpadminbar .quicklinks li#wp-admin-bar-stats{height:32px}#wpadminbar .quicklinks li#wp-admin-bar-stats a{height:32px;padding:0}#wpadminbar .quicklinks li#wp-admin-bar-stats a div{height:32px;width:95px;overflow:hidden;margin:0 10px}#wpadminbar .quicklinks li#wp-admin-bar-stats a:hover div{width:auto;margin:0 8px 0 10px}#wpadminbar .quicklinks li#wp-admin-bar-stats a img{height:24px;padding:4px 0;max-width:none;border:none}

#### What happened instead
CSS code is not inline, it is a minor change I am requesting, but it saves a little loading. Little easy fast change, small step to fast loading improvement. Thanks a lot !

Open modules/stats.php and locate the Jetpack Stats CSS for the wpadminbar stats item. Verify how the style block is currently emitted, then make it inline as requested and confirm the generated home-page markup contains the CSS inline.

Written by the indexing model from the issue text.