odp-util: Always serialise recirculation in upcall key.

odp-util: Always serialise recirculation in upcall key.

The userspace and kernel datapaths previously differed on their
treatment of the recirc_id and dp_hash fields when sending upcalls.
While the kernel datapath would always serialise these fields, the
userspace would not. When using the userspace datapath, this would cause
a mismatch between the odp flow key in an upcall compared to the one
that is serialised upon flow_dump.

This patch brings the userspace datapath behaviour back in line with the
kernel datapath by always serialising recirc_id and dp_hash to odp.

Signed-off-by: Joe Stringer <joestringer@nicira.com>
Acked-by: Andy Zhou <azhou@nicira.com>