dpdk: Remove batch sorting in userspace conntrack.

dpdk: Remove batch sorting in userspace conntrack.

Packet batch sorting is removed for three reasons:

1) The following patches for NAT change the locking
    marshalling so batching loses benefit.

2) For real mixtures of flows either in hypervisors
   or gateways, the batch sorting won't provide benefit
   and will just be a tax.

3) Code clarity.

Signed-off-by: Darrell Ball <dlu998@gmail.com>
Acked-by: Flavio Leitner <fbl@sysclose.org>
Acked-by: Daniele Di Proietto <diproiettod@ovn.org>
Signed-off-by: Ben Pfaff <blp@ovn.org>