sfc: pass the correctly bogus filter_id to rps_may_expire_flow()

When we inserted an ARFS filter for ndo_rx_flow_steer(), we didn't know
 what the filter ID would be, so we just returned 0.  Thus, we must also
 pass 0 as the filter ID when calling rps_may_expire_flow() for it, and
 rely on the flow_id to identify what we're talking about.

Fixes: 3af0f342

 ("sfc: replace asynchronous filter operations")
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>