phy: lpc18xx-usb-otg: error handling in lpc18xx_usb_otg_phy_power_on()

If regmap_update_bits() fails in lpc18xx_usb_otg_phy_power_on(),
lpc->clk is left enabled.

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

drivers/phy/phy-lpc18xx-usb-otg.c

@@ -60,8 +60,14 @@ static int lpc18xx_usb_otg_phy_power_on(struct phy *phy)
 		return ret;
 
 	/* The bit in CREG is cleared to enable the PHY */
-	return regmap_update_bits(lpc->reg, LPC18XX_CREG_CREG0,
+	ret = regmap_update_bits(lpc->reg, LPC18XX_CREG_CREG0,
 				  LPC18XX_CREG_CREG0_USB0PHY, 0);
+	if (ret) {
+		clk_disable(lpc->clk);
+		return ret;
+	}
+
+	return 0;
 }
 
 static int lpc18xx_usb_otg_phy_power_off(struct phy *phy)