ACPICA: Events: Cleanup of resetting the GPE handler to NULL before removing

ACPICA commit b2b18bb38045404e253f10787b8a4ae6e94cdee6

This patch prevents acpi_remove_gpe_handler() from leaking the stale
gpe_event_info->Dispatch.Handler to the caller to avoid possible NULL pointer
references. Lv Zheng.

Link: https://github.com/acpica/acpica/commit/b2b18bb3
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/acpica/evxface.c

@@ -896,6 +896,7 @@ acpi_remove_gpe_handler(acpi_handle gpe_device,
 	/* Remove the handler */
 
 	handler = gpe_event_info->dispatch.handler;
+	gpe_event_info->dispatch.handler = NULL;
 
 	/* Restore Method node (if any), set dispatch flags */