sfc: Make efx_mcdi_init() call efx_mcdi_handle_assertion()

This should probably be done during MCDI initialisation for any NIC.
Change efx_mcdi_init() to return an error code.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
diff --git a/drivers/net/ethernet/sfc/mcdi.c b/drivers/net/ethernet/sfc/mcdi.c
index 5132aba..2b9ef28 100644
--- a/drivers/net/ethernet/sfc/mcdi.c
+++ b/drivers/net/ethernet/sfc/mcdi.c
@@ -50,13 +50,10 @@
 	return &nic_data->mcdi;
 }
 
-void efx_mcdi_init(struct efx_nic *efx)
+int efx_mcdi_init(struct efx_nic *efx)
 {
 	struct efx_mcdi_iface *mcdi;
 
-	if (efx_nic_rev(efx) < EFX_REV_SIENA_A0)
-		return;
-
 	mcdi = efx_mcdi(efx);
 	init_waitqueue_head(&mcdi->wq);
 	spin_lock_init(&mcdi->iface_lock);
@@ -64,6 +61,9 @@
 	mcdi->mode = MCDI_MODE_POLL;
 
 	(void) efx_mcdi_poll_reboot(efx);
+
+	/* Recover from a failed assertion before probing */
+	return efx_mcdi_handle_assertion(efx);
 }
 
 static void efx_mcdi_copyin(struct efx_nic *efx, unsigned cmd,