net: ethernet: stmmac: drop unused variable in stm32mp1_set_mode()

Building with W=1 (cf.scripts/Makefile.extrawarn) outputs:
warning: variable ‘ret’ set but not used [-Wunused-but-set-variable]

Drop the unused 'ret' variable.
Signed-off-by: Christophe Roullier <christophe.roullier@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c

@@ -175,7 +175,7 @@ static int stm32mp1_set_mode(struct plat_stmmacenet_data *plat_dat)
 {
 	struct stm32_dwmac *dwmac = plat_dat->bsp_priv;
 	u32 reg = dwmac->mode_reg;
-	int val, ret;
+	int val;
 
 	switch (plat_dat->interface) {
 	case PHY_INTERFACE_MODE_MII:
@@ -211,8 +211,8 @@ static int stm32mp1_set_mode(struct plat_stmmacenet_data *plat_dat)
 	}
 
 	/* Need to update PMCCLRR (clear register) */
-	ret = regmap_write(dwmac->regmap, reg + SYSCFG_PMCCLRR_OFFSET,
-			   dwmac->ops->syscfg_eth_mask);
+	regmap_write(dwmac->regmap, reg + SYSCFG_PMCCLRR_OFFSET,
+		     dwmac->ops->syscfg_eth_mask);
 
 	/* Update PMCSETR (set register) */
 	return regmap_update_bits(dwmac->regmap, reg,