usb: phy: phy-generic: Check clk_prepare_enable() error

clk_prepare_enable() may fail, so we should better check its return
value and propagate it in the case of failure.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/phy/phy-generic.c

@@ -144,14 +144,18 @@ static irqreturn_t nop_gpio_vbus_thread(int irq, void *data)
 int usb_gen_phy_init(struct usb_phy *phy)
 {
 	struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
+	int ret;
 
 	if (!IS_ERR(nop->vcc)) {
 		if (regulator_enable(nop->vcc))
 			dev_err(phy->dev, "Failed to enable power\n");
 	}
 
-	if (!IS_ERR(nop->clk))
-		clk_prepare_enable(nop->clk);
+	if (!IS_ERR(nop->clk)) {
+		ret = clk_prepare_enable(nop->clk);
+		if (ret)
+			return ret;
+	}
 
 	nop_reset(nop);