bridge: Add flow in reconfiguring only after flow translation is possible.

bridge: Add flow in reconfiguring only after flow translation is possible.

If a bridge is in standalone mode and no controllers are configured, and
then reconfiguration (e.g. ovs-vsctl) adds an SLB or TCP-balanced bond,
and at the moment of reconfiguration active kernel flows exist that output
to the newly added bond, then ovs-vswitchd would segfault because the
bond's 'bond_hash' member is not yet initialized when flows are
retranslated as part of adding the flow that ensures normal standalone
switch behavior.

This commit fixes the problem by adding the flow later, after bonds have
been fully initialized.

NIC-443.
Reported-by: Dominic Curran <dominic.curran@citrix.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>