platform/x86/siemens: simatic-ipc-batt: fix logical error for BX-59A

platform/x86/siemens: simatic-ipc-batt: fix logical error for BX-59A

The variable "priv.devmode" is missing from if statement that leads
to a logical error. Add the missing variable to the if condition.

Fixes: c56beff20375 ("platform/x86/siemens: simatic-ipc-batt: add support for module BX-59A")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202308010001.BGYCSQrl-lkp@intel.com/
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: xingtong.wu <xingtong.wu@siemens.com>
Link: https://lore.kernel.org/r/20430802173844.2483-1-xingtong_wu@163.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>