CppEditor: Fix some clazy level0 warnings

Use leftRef() instead [-Wclazy-qstring-ref]
Use multi-arg instead [-Wclazy-qstring-arg]

Change-Id: I4aa67e0d518060cdec4f96cb7a03a9a499f28f27
Reviewed-by: Ivan Donchevskii <ivan.donchevskii@qt.io>
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/cppeditor/resourcepreviewhoverhandler.cpp

@@ -204,8 +204,7 @@ QString ResourcePreviewHoverHandler::makeTooltip() const
         ret += QString("<img src=\"file:///%1\" /><br/>").arg(m_resPath);
 
     ret += QString("<a href=\"file:///%1\">%2</a>")
-            .arg(m_resPath)
-            .arg(QDir::toNativeSeparators(m_resPath));
+               .arg(m_resPath, QDir::toNativeSeparators(m_resPath));
     return ret;
 }