title: Update user meta on wp_login
body: <p>This must be a very simple issue but I'm struggling with it, all I'm trying to do with this function is update a custom field to 0 upon user login. I've tried a few variants. This issue is that the custom field does not update.</p>
  
  <p>I imagine the issue is I'm not getting the current user info properly?</p>
  
  <pre><code>function expire_tier_discount( $user_id ) { 
      update_user_meta( $user_id, 'tier_progress_value', 0);
  }
  add_action('wp_login', 'expire_tier_discount');
  </code></pre>
  
  <p>another attempt:</p>
  
  <pre><code>function expire_tier_discount() { 
      update_user_meta( $user-&gt;ID, 'tier_progress_value', 0);
  }
  add_action('wp_login', 'expire_tier_discount');
  </code></pre>
  
  <p>another:</p>
  
  <pre><code>function expire_tier_discount( $user ) { 
      $user = wp_get_current_user();
      update_user_meta( $user-&gt;ID, 'tier_progress_value', 0);
  }
  add_action('wp_login', 'expire_tier_discount');
  </code></pre>