platform/x86: dell-wmi-sysman: Fix class device unregistration

BugLink: https://bugs.launchpad.net/bugs/2122072

[ Upstream commit 314e5ad4782d08858b3abc325c0487bd2abc23a1 ]

Devices under the firmware_attributes_class do not have unique a dev_t.
Therefore, device_unregister() should be used instead of
device_destroy(), since the latter may match any device with a given
dev_t.

Fixes: e8a60aa ("platform/x86: Introduce support for Systems Management Driver over WMI for Dell Systems")
Signed-off-by: Kurt Borja <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Ilpo Järvinen <[email protected]>
Signed-off-by: Ilpo Järvinen <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Noah Wager <[email protected]>
Signed-off-by: Stefan Bader <[email protected]>

Author: kuu-rt

drivers/platform/x86/dell/dell-wmi-sysman/sysman.c

@@ -597,7 +597,7 @@ static int __init sysman_init(void)
 	release_attributes_data();
 
 err_destroy_classdev:
-	device_destroy(&firmware_attributes_class, MKDEV(0, 0));
+	device_unregister(wmi_priv.class_dev);
 
 err_exit_bios_attr_pass_interface:
 	exit_bios_attr_pass_interface();
@@ -611,7 +611,7 @@ static int __init sysman_init(void)
 static void __exit sysman_exit(void)
 {
 	release_attributes_data();
-	device_destroy(&firmware_attributes_class, MKDEV(0, 0));
+	device_unregister(wmi_priv.class_dev);
 	exit_bios_attr_set_interface();
 	exit_bios_attr_pass_interface();
 }