From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
The commit 
1fdd407f4e3f2ecb453954cbebb6c22491c61853 incorrectly made driver
abort loading when known GUID is present when it should have done exactly
the opposite.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Len Brown <len.brown@intel.com>
        int err;
        acpi_status status;
 
-       if (wmi_has_guid(DELL_EVENT_GUID)) {
+       if (!wmi_has_guid(DELL_EVENT_GUID)) {
                printk(KERN_WARNING "dell-wmi: No known WMI GUID found\n");
                return -ENODEV;
        }