mfd: intel_quark_i2c_gpio: Remove clock tree on error path

There is a potential resource leak in case when ->probe() fails. We have to
unregister and remove clock tree which is done here.

This is a follow up to previously pushed commit c4726abc ("mfd:
intel_quark_i2c_gpio: Use clkdev_create()") that prevents double free() when
clkdev_drop() followed by kfree() in devm_kcalloc() release stage.

I leave Fixes tag here, but the backporting will require to backport the commit
c4726abc ("mfd: intel_quark_i2c_gpio: Use clkdev_create()") first.

Cc: stable@vger.kernel.org
Fixes: 60ae5b9f (mfd: intel_quark_i2c_gpio: Add Intel Quark X1000 I2C-GPIO MFD Driver)
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/intel_quark_i2c_gpio.c

@@ -139,6 +139,7 @@ static int intel_quark_register_i2c_clk(struct intel_quark_mfd *quark_mfd)
 						INTEL_QUARK_I2C_CONTROLLER_CLK);
 
 	if (!quark_mfd->i2c_clk_lookup) {
+		clk_unregister(quark_mfd->i2c_clk);
 		dev_err(&pdev->dev, "Fixed clk register failed\n");
 		return -ENOMEM;
 	}
@@ -150,7 +151,7 @@ static void intel_quark_unregister_i2c_clk(struct pci_dev *pdev)
 {
 	struct intel_quark_mfd *quark_mfd = dev_get_drvdata(&pdev->dev);
 
-	if (!quark_mfd->i2c_clk || !quark_mfd->i2c_clk_lookup)
+	if (!quark_mfd->i2c_clk_lookup)
 		return;
 
 	clkdev_drop(quark_mfd->i2c_clk_lookup);
@@ -246,25 +247,33 @@ static int intel_quark_mfd_probe(struct pci_dev *pdev,
 	quark_mfd = devm_kzalloc(&pdev->dev, sizeof(*quark_mfd), GFP_KERNEL);
 	if (!quark_mfd)
 		return -ENOMEM;
+
 	quark_mfd->pdev = pdev;
+	dev_set_drvdata(&pdev->dev, quark_mfd);
 
 	ret = intel_quark_register_i2c_clk(quark_mfd);
 	if (ret)
 		return ret;
 
-	dev_set_drvdata(&pdev->dev, quark_mfd);
-
 	ret = intel_quark_i2c_setup(pdev, &intel_quark_mfd_cells[1]);
 	if (ret)
-		return ret;
+		goto err_unregister_i2c_clk;
 
 	ret = intel_quark_gpio_setup(pdev, &intel_quark_mfd_cells[0]);
 	if (ret)
-		return ret;
+		goto err_unregister_i2c_clk;
 
-	return mfd_add_devices(&pdev->dev, 0, intel_quark_mfd_cells,
+	ret = mfd_add_devices(&pdev->dev, 0, intel_quark_mfd_cells,
 			      ARRAY_SIZE(intel_quark_mfd_cells), NULL, 0,
 			      NULL);
+	if (ret)
+		goto err_unregister_i2c_clk;
+
+	return 0;
+
+err_unregister_i2c_clk:
+	intel_quark_unregister_i2c_clk(pdev);
+	return ret;
 }
 
 static void intel_quark_mfd_remove(struct pci_dev *pdev)