platform/x86: dell-sysman: Improve instance detection

The WMI driver core already knows how many WMI object instances
are available, use this information instead of probing the WMI object
manually.

Compile-tested only.
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20230430203153.5587-3-W_Armin@gmx.deReviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

drivers/platform/x86/dell/dell-wmi-sysman/sysman.c

@@ -303,16 +303,13 @@ union acpi_object *get_wmiobj_pointer(int instance_id, const char *guid_string)
  */
 int get_instance_count(const char *guid_string)
 {
-	union acpi_object *wmi_obj = NULL;
-	int i = 0;
+	int ret;
 
-	do {
-		kfree(wmi_obj);
-		wmi_obj = get_wmiobj_pointer(i, guid_string);
-		i++;
-	} while (wmi_obj);
+	ret = wmi_instance_count(guid_string);
+	if (ret < 0)
+		return 0;
 
-	return (i-1);
+	return ret;
 }
 
 /**