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/common/zstream.cpp

@@ -335,11 +335,8 @@ bool wxZlibOutputStream::Close()
  {
   DoFlush(true);
    deflateEnd(m_deflate);
-   delete m_deflate;
-
-  m_deflate = NULL;
-   delete[] m_z_buffer;
-  m_z_buffer = NULL;
+   wxDELETE(m_deflate);
+   wxDELETEA(m_z_buffer);
 
   return wxFilterOutputStream::Close() && IsOk();
  }