ACPI: x86: Add adev NULL check to acpi_quirk_skip_serdev_enumeration()

acpi_dev_hid_match() does not check for adev == NULL, dereferencing
it unconditional.

Add a check for adev being NULL before calling acpi_dev_hid_match().

At the moment acpi_quirk_skip_serdev_enumeration() is never called with
a controller_parent without an ACPI companion, but better safe than sorry.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patch.msgid.link/20241109220028.83047-1-hdegoede@redhat.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Author: jwrdegoede

drivers/acpi/x86/utils.c

@@ -536,7 +536,7 @@ int acpi_quirk_skip_serdev_enumeration(struct device *controller_parent, bool *s
 	 * Set skip to true so that the tty core creates a serdev ctrl device.
 	 * The backlight driver will manually create the serdev client device.
 	 */
-	if (acpi_dev_hid_match(adev, "DELL0501")) {
+	if (adev && acpi_dev_hid_match(adev, "DELL0501")) {
 		*skip = true;
 		/*
 		 * Create a platform dev for dell-uart-backlight to bind to.