usb: bdc: Fix a resource leak in the error handling path of 'bdc_probe()'

If an error occurs after a successful 'clk_prepare_enable()' call, it must
be undone by a corresponding 'clk_disable_unprepare()' call.
This call is already present in the remove function.

Add this call in the error handling path and reorder the code so that the
'clk_prepare_enable()' call happens later in the function.
The goal is to have as much managed resources functions as possible
before the 'clk_prepare_enable()' call in order to keep the error handling
path simple.

While at it, remove the now unneeded 'clk' variable.

Fixes: c87dca0478 ("usb: bdc: Add clock enable for new chips with a separate BDC clock")
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/f8a4a6897deb0c8cb2e576580790303550f15fcd.1629314734.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/udc/bdc/bdc_core.c

@@ -488,27 +488,14 @@ static int bdc_probe(struct platform_device *pdev)
 	int irq;
 	u32 temp;
 	struct device *dev = &pdev->dev;
-	struct clk *clk;
 	int phy_num;
 
 	dev_dbg(dev, "%s()\n", __func__);
 
-	clk = devm_clk_get_optional(dev, "sw_usbd");
-	if (IS_ERR(clk))
-		return PTR_ERR(clk);
-
-	ret = clk_prepare_enable(clk);
-	if (ret) {
-		dev_err(dev, "could not enable clock\n");
-		return ret;
-	}
-
 	bdc = devm_kzalloc(dev, sizeof(*bdc), GFP_KERNEL);
 	if (!bdc)
 		return -ENOMEM;
 
-	bdc->clk = clk;
-
 	bdc->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(bdc->regs))
 		return PTR_ERR(bdc->regs);
@@ -545,10 +532,20 @@ static int bdc_probe(struct platform_device *pdev)
 		}
 	}
 
+	bdc->clk = devm_clk_get_optional(dev, "sw_usbd");
+	if (IS_ERR(bdc->clk))
+		return PTR_ERR(bdc->clk);
+
+	ret = clk_prepare_enable(bdc->clk);
+	if (ret) {
+		dev_err(dev, "could not enable clock\n");
+		return ret;
+	}
+
 	ret = bdc_phy_init(bdc);
 	if (ret) {
 		dev_err(bdc->dev, "BDC phy init failure:%d\n", ret);
-		return ret;
+		goto disable_clk;
 	}
 
 	temp = bdc_readl(bdc->regs, BDC_BDCCAP1);
@@ -581,6 +578,8 @@ cleanup:
 	bdc_hw_exit(bdc);
 phycleanup:
 	bdc_phy_exit(bdc);
+disable_clk:
+	clk_disable_unprepare(bdc->clk);
 	return ret;
 }