net: fec: drop check for clk==NULL before calling clk_*

clk_prepare, clk_enable and their counterparts (at least the common clk
ones, but also most others) do check for the clk being NULL anyhow (and
return 0 then), so there is no gain when the caller checks, too.

Signed-off-by: Uwe Kleine-König <[e-mail]>
Acked-by: Fugang Duan <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/freescale/fec_main.c

···
 		ret = clk_prepare_enable(fep->clk_ahb);
 		if (ret)
 			return ret;
-		if (fep->clk_enet_out) {
-			ret = clk_prepare_enable(fep->clk_enet_out);
-			if (ret)
-				goto failed_clk_enet_out;
-		}
+
+		ret = clk_prepare_enable(fep->clk_enet_out);
+		if (ret)
+			goto failed_clk_enet_out;
+
 		if (fep->clk_ptp) {
 			mutex_lock(&fep->ptp_clk_mutex);
 			ret = clk_prepare_enable(fep->clk_ptp);
···
 			}
 			mutex_unlock(&fep->ptp_clk_mutex);
 		}
-		if (fep->clk_ref) {
-			ret = clk_prepare_enable(fep->clk_ref);
-			if (ret)
-				goto failed_clk_ref;
-		}
+
+		ret = clk_prepare_enable(fep->clk_ref);
+		if (ret)
+			goto failed_clk_ref;
 	} else {
 		clk_disable_unprepare(fep->clk_ahb);
-		if (fep->clk_enet_out)
-			clk_disable_unprepare(fep->clk_enet_out);
+		clk_disable_unprepare(fep->clk_enet_out);
 		if (fep->clk_ptp) {
 			mutex_lock(&fep->ptp_clk_mutex);
 			clk_disable_unprepare(fep->clk_ptp);
 			fep->ptp_clk_on = false;
 			mutex_unlock(&fep->ptp_clk_mutex);
 		}
-		if (fep->clk_ref)
-			clk_disable_unprepare(fep->clk_ref);
+		clk_disable_unprepare(fep->clk_ref);
 	}
 
 	return 0;