Fix broken top-level style name (php-debugbar#348)

The top-level debug bar style is 'phpdebugbar' not 'debugbar'.  This was
preventing rendered HtmlDumper dumps from styling correctly.

Author: james-johnston-thumbtack

src/DebugBar/DataFormatter/DebugBarVarDumper.php

@@ -45,7 +45,7 @@ class DebugBarVarDumper implements AssetProvider
     /** @var VarCloner */
     protected $cloner;
 
-    /** @var Debu */
+    /** @var DebugBarHtmlDumper */
     protected $dumper;
 
     /**

src/DebugBar/DataFormatter/VarDumper/DebugBarHtmlDumper.php

@@ -12,6 +12,6 @@ class DebugBarHtmlDumper extends HtmlDumper
 {
     public function getDumpHeaderByDebugBar() {
         // getDumpHeader is protected:
-        return str_replace('pre.sf-dump', '.debugbar pre.sf-dump', $this->getDumpHeader());
+        return str_replace('pre.sf-dump', '.phpdebugbar pre.sf-dump', $this->getDumpHeader());
     }
 }