ASoC: pxa2xx-ac97: fix error handling for reset GPIO descriptor

The reset GPIO obtained via devm_gpiod_get() may return an ERR_PTR()
when the GPIO is missing or an error occurs. The current code
unconditionally assigns PTR_ERR() to ret and later dereferences
rst_gpio via desc_to_gpio(), which is incorrect when rst_gpio is an
error pointer.

Rework the logic to first check IS_ERR(rst_gpio) before converting the
descriptor. Handle -ENOENT by disabling reset GPIO support, and return
other errors to the caller as expected.

Fixes: c76d50b ("ASoC: ac97: Convert to GPIO descriptors")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Closes: https://lore.kernel.org/r/202604041426.i2C1xqHk-lkp@intel.com/
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://patch.msgid.link/20260413-ac97-v1-1-b44b9e084307@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: MrVan

sound/arm/pxa2xx-ac97-lib.c

@@ -331,12 +331,15 @@ int pxa2xx_ac97_hw_probe(struct platform_device *dev)
 	if (dev->dev.of_node) {
 		/* Assert reset using GPIOD_OUT_HIGH, because reset is GPIO_ACTIVE_LOW */
 		rst_gpio = devm_gpiod_get(&dev->dev, "reset", GPIOD_OUT_HIGH);
-		ret = PTR_ERR(rst_gpio);
-		if (ret == -ENOENT)
-			reset_gpio = -1;
-		else if (ret)
-			return ret;
-		reset_gpio = desc_to_gpio(rst_gpio);
+		if (IS_ERR(rst_gpio)) {
+			ret = PTR_ERR(rst_gpio);
+			if (ret == -ENOENT)
+				reset_gpio = -1;
+			else if (ret)
+				return ret;
+		} else {
+			reset_gpio = desc_to_gpio(rst_gpio);
+		}
 	} else {
 		if (cpu_is_pxa27x())
 			reset_gpio = 113;