stmmac: dwmac-sti: remove clk NULL checks

Since sti_dwmac_parse_data() sets dwmac->clk to NULL if not clock was
provided in DT and NULL is a valid clock there is no need to check for
NULL before using this clock.
Signed-off-by: Joachim Eastwood <manabian@gmail.com>
Acked-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Tested-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -191,7 +191,7 @@ static void stih4xx_fix_retime_src(void *priv, u32 spd)
 		}
 	}
 
-	if (src == TX_RETIME_SRC_CLKGEN && dwmac->clk && freq)
+	if (src == TX_RETIME_SRC_CLKGEN && freq)
 		clk_set_rate(dwmac->clk, freq);
 
 	regmap_update_bits(dwmac->regmap, reg, STIH4XX_RETIME_SRC_MASK,
@@ -222,7 +222,7 @@ static void stid127_fix_retime_src(void *priv, u32 spd)
 			freq = DWMAC_2_5MHZ;
 	}
 
-	if (dwmac->clk && freq)
+	if (freq)
 		clk_set_rate(dwmac->clk, freq);
 
 	regmap_update_bits(dwmac->regmap, reg, STID127_RETIME_SRC_MASK, val);
@@ -238,7 +238,6 @@ static int sti_dwmac_init(struct platform_device *pdev, void *priv)
 	u32 reg = dwmac->ctrl_reg;
 	u32 val;
 
-	if (dwmac->clk)
 	clk_prepare_enable(dwmac->clk);
 
 	if (of_property_read_bool(np, "st,gmac_en"))
@@ -258,7 +257,6 @@ static void sti_dwmac_exit(struct platform_device *pdev, void *priv)
 {
 	struct sti_dwmac *dwmac = priv;
 
-	if (dwmac->clk)
 	clk_disable_unprepare(dwmac->clk);
 }
 static int sti_dwmac_parse_data(struct sti_dwmac *dwmac,