<div>
  <span id="tuned-status-tooltip" data-html="true">
     <button class="link-button action-trigger" id="tuned-status-button"></button>
  </span>
</div>

<div>
  <span id="tuned-status-tooltip" data-html="true">
     <button class="pf-c-button pf-m-link pf-m-inline action-trigger" id="tuned-status-button"></button>
  </span>
</div>

Add proper PF4 classes for inline button to performance profile button
system: Add proper PF4 classes for inline button to performance profile button

With these classes the font-size will be now the same like the rest of
the inline buttons.
