platform/x86: peaq-wmi: Remove unnecessary checks from peaq_wmi_exit

peaq_wmi_exit will only ever get called if peaq_wmi_init succeeds, so
there is no need to repeat the checks from peaq_wmi_init.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>