net: stmmac: Remove useless test before clk_disable_unprepare

clk_disable_unprepare() already checks that the clock pointer is valid.
No need to test it before calling it.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c

@@ -1104,29 +1104,19 @@ static int gmac_clk_enable(struct rk_priv_data *bsp_priv, bool enable)
 	} else {
 		if (bsp_priv->clk_enabled) {
 			if (phy_iface == PHY_INTERFACE_MODE_RMII) {
-				if (!IS_ERR(bsp_priv->mac_clk_rx))
-					clk_disable_unprepare(
-						bsp_priv->mac_clk_rx);
+				clk_disable_unprepare(bsp_priv->mac_clk_rx);
 
-				if (!IS_ERR(bsp_priv->clk_mac_ref))
-					clk_disable_unprepare(
-						bsp_priv->clk_mac_ref);
+				clk_disable_unprepare(bsp_priv->clk_mac_ref);
 
-				if (!IS_ERR(bsp_priv->clk_mac_refout))
-					clk_disable_unprepare(
-						bsp_priv->clk_mac_refout);
+				clk_disable_unprepare(bsp_priv->clk_mac_refout);
 			}
 
-			if (!IS_ERR(bsp_priv->clk_phy))
 			clk_disable_unprepare(bsp_priv->clk_phy);
 
-			if (!IS_ERR(bsp_priv->aclk_mac))
 			clk_disable_unprepare(bsp_priv->aclk_mac);
 
-			if (!IS_ERR(bsp_priv->pclk_mac))
 			clk_disable_unprepare(bsp_priv->pclk_mac);
 
-			if (!IS_ERR(bsp_priv->mac_clk_tx))
 			clk_disable_unprepare(bsp_priv->mac_clk_tx);
 			/**
 			 * if (!IS_ERR(bsp_priv->clk_mac))