ssa_path_record.c: Use destroy and build rather than rebuild in ssa_pr_reinit_context

ssa_pr_rebuild_indexes compares index's epoch and SMDB's epoch.
In case of SM failover/handover new SMDB could have the same
epoch like last pushed SMDB from previous core.

Signed-off-by: Sasha Kotchubievsky <sashakot@mellanox.com>
Signed-off-by: Hal Rosenstock <hal@mellanox.com>