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/tx.c b/drivers/net/ethernet/sfc/tx.c
index 72f0fbc..5cb81fa 100644
--- a/drivers/net/ethernet/sfc/tx.c
+++ b/drivers/net/ethernet/sfc/tx.c
@@ -446,10 +446,8 @@
 	    likely(efx->port_enabled) &&
 	    likely(netif_device_present(efx->net_dev))) {
 		fill_level = tx_queue->insert_count - tx_queue->read_count;
-		if (fill_level < EFX_TXQ_THRESHOLD(efx)) {
-			EFX_BUG_ON_PARANOID(!efx_dev_registered(efx));
+		if (fill_level < EFX_TXQ_THRESHOLD(efx))
 			netif_tx_wake_queue(tx_queue->core_txq);
-		}
 	}
 
 	/* Check whether the hardware queue is now empty */