platform/x86: msi-wmi-platform: Workaround a ACPI firmware bug

The ACPI byte code inside the ACPI control method responsible for
handling the WMI method calls uses a global buffer for constructing
the return value, yet the ACPI control method itself is not marked
as "Serialized".
This means that calling WMI methods on this WMI device is not
thread-safe, as concurrent WMI method calls will corrupt the global
buffer.

Fix this by serializing the WMI method calls using a mutex.

Cc: stable@vger.kernel.org # 6.x.x: 912d614a: platform/x86: msi-wmi-platform: Rename "data" variable
Fixes: 9c0beb6b ("platform/x86: wmi: Add MSI WMI Platform driver")
Tested-by: Antheas Kapenekakis <lkml@antheas.dev>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20250414140453.7691-2-W_Armin@gmx.de


Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>