title: no-descending-specificity error reported on two different classes
body: <p>I'm using stylelint with the standard format <code>stylelint-config-standard</code> and I'm encountering this error a lot with my stylesheets:</p>
  
  <p><code>no-descending-specificity</code></p>
  
  <p>An example of where it's happening is when I have CSS like:</p>
  
  <pre><code>.footer__social li a {}
  
  .footer__social li a:hover {}
  
  .footer__links li a {}
  
  .footer__links li a:hover {}
  </code></pre>
  
  <p>and then I get the following error:</p>
  
  <p><code>Expected selector ".footer__links li a" to come before selector ".footer__social li a:hover"   no-descending-specificity</code>.</p>
  
  <p>A lot of the CSS will be like this because of using SASS like:</p>
  
  <pre><code>.footer__links {
    a {
      a:hover {}
    }
  }
  </code></pre>
  
  <p>I don't want to have disable this if I can...</p>
  
  <p>But why is it complaining? as it's <strong>two separate classes</strong>: <code>.footer__social</code> and <code>.footer__links</code>.</p>
  
  <p>So these two declarations for the anchors don't have any effect on each other because they have different parent classes so what's the issue? I'd understand something like:</p>
  
  <pre><code>.footer__links a:hover {}
  a {}
  </code></pre>
  
  <p>But I don't see the issue if it's two different classes...</p>