Support route deletion entries in SVP_R_LOG_ACK.

*** 313,323 ****
   * needs to be processed promptly; however, the information is hopefully going
   * to be relatively infrequent relative to the normal flow of information.
   *
   * The shoot down information needs to be done on a per-backend basis. The
   * general design is that we'll have a single query for this which can fire on a
!  * 5-10s period, we randmoize the latter part to give us a bit more load
   * spreading. If we complete because there's no work to do, then we wait the
   * normal period. If we complete, but there's still work to do, we'll go again
   * after a second.
   *
   * A shootdown has a few different parts. We first receive a list of items to
--- 313,323 ----
   * needs to be processed promptly; however, the information is hopefully going
   * to be relatively infrequent relative to the normal flow of information.
   *
   * The shoot down information needs to be done on a per-backend basis. The
   * general design is that we'll have a single query for this which can fire on a
!  * 5-10s period, we randomize the latter part to give us a bit more load
   * spreading. If we complete because there's no work to do, then we wait the
   * normal period. If we complete, but there's still work to do, we'll go again
   * after a second.
   *
   * A shootdown has a few different parts. We first receive a list of items to
*** 540,556 ****
--- 540,569 ----
          libvarpd_plugin_query_reply(svl->svl_u.svl_route.svl_handle,
              VARPD_LOOKUP_OK);
          umem_cache_free(svp_lookup_cache, svl);
  }
  
+ /*
+  * Tell the overlay instance to flush out entries matcthing this route.
+  * See libvarpd_route_flush() for more.
+  */
+ static void
+ svp_route_shootdown_cb(svp_t *svp, uint8_t *srcip, uint8_t *dstip,
+     uint8_t src_prefixlen, uint8_t dst_prefixlen, uint16_t vlan_id)
+ {
+         libvarpd_route_flush(svp->svp_hdl, srcip, dstip, src_prefixlen,
+             dst_prefixlen, vlan_id);
+ }
+ 
  static svp_cb_t svp_defops = {
          svp_vl2_lookup_cb,
          svp_vl3_lookup_cb,
          svp_vl2_invalidate_cb,
          svp_vl3_inject_cb,
          svp_shootdown_cb,
          svp_route_lookup_cb,
+         svp_route_shootdown_cb
  };
  
  static boolean_t
  varpd_svp_valid_dest(overlay_plugin_dest_t dest)
  {