python3: Use Py_TYPE() instead of self->ob_type

As described here:

http://python3porting.com/cextensions.html#object-initialization

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

Author: Andy Grover

python-ethtool/etherinfo_obj.c

@@ -42,7 +42,7 @@ static void _ethtool_etherinfo_dealloc(PyEtherInfo *self)
 	close_netlink(self);
         Py_XDECREF(self->device);    self->device = NULL;
         Py_XDECREF(self->hwaddress); self->hwaddress = NULL;
-	self->ob_type->tp_free((PyObject*)self);
+	Py_TYPE(self)->tp_free((PyObject*)self);
 }