platform/x86: huawei-wmi: Don't leak memory on the exit

We have to clean memory resources allocated during init.

Fixes: 7532afb35012 ("platform/x86: huawei-wmi: Move to platform driver")
Cc: Ayman Bagabas <ayman.bagabas@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

drivers/platform/x86/huawei-wmi.c

@@ -885,6 +885,8 @@ static __exit void huawei_wmi_exit(void)
 {
 	platform_device_unregister(huawei_wmi->pdev);
 	platform_driver_unregister(&huawei_wmi_driver);
+
+	kfree(huawei_wmi);
 }
 
 module_init(huawei_wmi_init);