datapath: remove unnecessary EXPORT_SYMBOLs

datapath: remove unnecessary EXPORT_SYMBOLs

Upstream commit:
    commit 76e4cc7731a1e0c07e202999b9834f9d9be66de4
    Author: Jiri Benc <jbenc@redhat.com>
    Date:   Wed Oct 19 11:26:37 2016 +0200

    openvswitch: remove unnecessary EXPORT_SYMBOLs

    Some symbols exported to other modules are really used only by
    openvswitch.ko. Remove the exports.

    Tested by loading all 4 openvswitch modules, nothing breaks.

    Signed-off-by: Jiri Benc <jbenc@redhat.com>
    Acked-by: Pravin B Shelar <pshelar@ovn.org>
    Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jarno Rajahalme <jarno@ovn.org>
Signed-off-by: Joe Stringer <joe@ovn.org>