sfc: Remove remnants of on-load self-test

The out-of-tree version of the sfc driver used to run a self-test on
each device before registering it.  Although this was never included
in-tree, some functions have checks for this special case which is not
really possible.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
diff --git a/drivers/net/ethernet/sfc/nic.c b/drivers/net/ethernet/sfc/nic.c
index de7aa1c..cd250f1 100644
--- a/drivers/net/ethernet/sfc/nic.c
+++ b/drivers/net/ethernet/sfc/nic.c
@@ -726,11 +726,9 @@
 		tx_queue = efx_channel_get_tx_queue(
 			channel, tx_ev_q_label % EFX_TXQ_TYPES);
 
-		if (efx_dev_registered(efx))
-			netif_tx_lock(efx->net_dev);
+		netif_tx_lock(efx->net_dev);
 		efx_notify_tx_desc(tx_queue);
-		if (efx_dev_registered(efx))
-			netif_tx_unlock(efx->net_dev);
+		netif_tx_unlock(efx->net_dev);
 	} else if (EFX_QWORD_FIELD(*event, FSF_AZ_TX_EV_PKT_ERR) &&
 		   EFX_WORKAROUND_10727(efx)) {
 		efx_schedule_reset(efx, RESET_TYPE_TX_DESC_FETCH);