Input: lpc32xx-keys - use guard notation when acquiring mutex

This makes the code more compact and error handling more robust
by ensuring that mutexes are released in all code paths when control
leaves critical section.

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Dmitry Torokhov <[e-mail]>

drivers/input/keyboard/lpc32xx-keys.c

···
 	struct lpc32xx_kscan_drv *kscandat = platform_get_drvdata(pdev);
 	struct input_dev *input = kscandat->input;
 
-	mutex_lock(&input->mutex);
+	guard(mutex)(&input->mutex);
 
 	if (input_device_enabled(input)) {
 		/* Clear IRQ and disable clock */
···
 		clk_disable_unprepare(kscandat->clk);
 	}
 
-	mutex_unlock(&input->mutex);
 	return 0;
 }
 
···
 	struct platform_device *pdev = to_platform_device(dev);
 	struct lpc32xx_kscan_drv *kscandat = platform_get_drvdata(pdev);
 	struct input_dev *input = kscandat->input;
-	int retval = 0;
+	int error;
 
-	mutex_lock(&input->mutex);
+	guard(mutex)(&input->mutex);
 
 	if (input_device_enabled(input)) {
 		/* Enable clock and clear IRQ */
-		retval = clk_prepare_enable(kscandat->clk);
-		if (retval == 0)
-			writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
+		error = clk_prepare_enable(kscandat->clk);
+		if (error)
+			return error;
+
+		writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
 	}
 
-	mutex_unlock(&input->mutex);
-	return retval;
+	return 0;
 }
 
 static DEFINE_SIMPLE_DEV_PM_OPS(lpc32xx_kscan_pm_ops, lpc32xx_kscan_suspend,