Compile fix after latest cleanup.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_4_BRANCH@17659 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/datstrm.cpp

@@ -117,7 +117,7 @@ wxString wxDataInputStream::ReadString()
     delete[] tmp;
 #else
     wxString ret;
-    m_input->Read(s.GetWriteBuf(len), len);
+    m_input->Read( ret.GetWriteBuf(len), len);
     ret.UngetWriteBuf();
 #endif
     return ret;