python3: set PyEtherInfo.tp_flags to Py_TPFLAGS_DEFAULT

The tp_flags field is basically feature flags. The Py2 features are assumed
for Py3 and thus are no longer defined. Just use Py_TPFLAGS_DEFAULT.
Furthermore, Py_TPFLAGS_DEFAULT should also work when building against
Python 2 -- TPFLAGS_DEFAULT includes TPFLAGS_HAVE_CLASS.

Signed-off-by: Andy Grover <agrover@redhat.com>

Author: Andy Grover

python-ethtool/etherinfo_obj.c

@@ -280,7 +280,7 @@ PyTypeObject PyEtherInfo_Type = {
     PyVarObject_HEAD_INIT(NULL, 0)
     .tp_name = "ethtool.etherinfo",
     .tp_basicsize = sizeof(PyEtherInfo),
-    .tp_flags = Py_TPFLAGS_HAVE_CLASS,
+    .tp_flags = Py_TPFLAGS_DEFAULT,
     .tp_dealloc = (destructor)_ethtool_etherinfo_dealloc,
     .tp_str = (reprfunc)_ethtool_etherinfo_str,
     .tp_getattro = (getattrofunc)_ethtool_etherinfo_getter,