sfc: Run event/IRQ self-test asynchronously when interface is brought up

Generate a test event on each event queue whenever the interface is
brought up, then after 1 second check that we have either handled a
test event or handled another IRQ for each event queue.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
diff --git a/drivers/net/ethernet/sfc/efx.h b/drivers/net/ethernet/sfc/efx.h
index 4debfe0..be8f915 100644
--- a/drivers/net/ethernet/sfc/efx.h
+++ b/drivers/net/ethernet/sfc/efx.h
@@ -148,7 +148,7 @@
 
 static inline void efx_schedule_channel_irq(struct efx_channel *channel)
 {
-	channel->last_irq_cpu = raw_smp_processor_id();
+	channel->event_test_cpu = raw_smp_processor_id();
 	efx_schedule_channel(channel);
 }