platform/x86: toshiba_acpi: Check ACPI_COMPANION() against NULL

Every platform driver can be forced to match a device that doesn't match
its list of device IDs because of device_match_driver_override(), so
platform drivers that rely on the existence of a device's ACPI companion
object need to verify its presence.

Accordingly, add a requisite ACPI_COMPANION() check against NULL to the
platform/x86 toshiba_acpi driver.

Fixes: 246d6ce ("platform/x86: toshiba_acpi: Convert ACPI driver to a platform one")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/1973170.CQOukoFCf9@rafael.j.wysocki
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

Author: rafaeljw

drivers/platform/x86/toshiba_acpi.c

@@ -3374,7 +3374,7 @@ static const struct dmi_system_id toshiba_dmi_quirks[] __initconst = {
 
 static int toshiba_acpi_probe(struct platform_device *pdev)
 {
-	struct acpi_device *acpi_dev = ACPI_COMPANION(&pdev->dev);
+	struct acpi_device *acpi_dev;
 	struct toshiba_acpi_dev *dev;
 	const char *hci_method;
 	u32 dummy;
@@ -3383,6 +3383,10 @@ static int toshiba_acpi_probe(struct platform_device *pdev)
 	if (toshiba_acpi)
 		return -EBUSY;
 
+	acpi_dev = ACPI_COMPANION(&pdev->dev);
+	if (!acpi_dev)
+		return -ENODEV;
+
 	pr_info("Toshiba Laptop ACPI Extras version %s\n",
 	       TOSHIBA_ACPI_VERSION);