sfc: Remove some unreachable error paths

Some functions return an error code which is always 0.  Change their
return types to void and simplify their callers accordingly.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/net/sfc/rx.h b/drivers/net/sfc/rx.h
index 187b110..0e88a9d 100644
--- a/drivers/net/sfc/rx.h
+++ b/drivers/net/sfc/rx.h
@@ -14,7 +14,7 @@
 
 int efx_probe_rx_queue(struct efx_rx_queue *rx_queue);
 void efx_remove_rx_queue(struct efx_rx_queue *rx_queue);
-int efx_init_rx_queue(struct efx_rx_queue *rx_queue);
+void efx_init_rx_queue(struct efx_rx_queue *rx_queue);
 void efx_fini_rx_queue(struct efx_rx_queue *rx_queue);
 
 int efx_lro_init(struct net_lro_mgr *lro_mgr, struct efx_nic *efx);