Use wxDELETE() and wxDELETEA() when possible.

Use wxDELETE[A]() functions which automatically NULL out their arguments after
deleting them instead of doing it manually.

Closes #9685.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@64656 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/html/htmlpars.cpp

@@ -250,8 +250,7 @@ void wxHtmlParser::DestroyDOMTree()
     }
     m_Tags = m_CurTag = NULL;
 
-    delete m_TextPieces;
-    m_TextPieces = NULL;
+    wxDELETE(m_TextPieces);
 }
 
 void wxHtmlParser::DoParsing()