[gnome-settings-daemon/benzea/fix-no-usbguard-warning] usb-protection: Do not warn about ServiceUnknown errors for USBGuard

[Benjamin Berg <bberg src gnome org>]

commit affebf890fdc032f246490f6bcd8f2c7777c7be1
Author: Benjamin Berg <bberg redhat com>
Date:   Fri Nov 20 11:23:08 2020 +0100

    usb-protection: Do not warn about ServiceUnknown errors for USBGuard
    
    It is expected for USBGuard to not be installed on many systems. We
    should not warn about that DBus error, as it does not indicate an issue.
    
    Closes: #567

 plugins/usb-protection/gsd-usb-protection-manager.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/plugins/usb-protection/gsd-usb-protection-manager.c 
b/plugins/usb-protection/gsd-usb-protection-manager.c
index 0b0557fe..63a4e0d7 100644
--- a/plugins/usb-protection/gsd-usb-protection-manager.c
+++ b/plugins/usb-protection/gsd-usb-protection-manager.c
@@ -154,7 +154,8 @@ dbus_call_log_error (GObject      *source_object,
         result = g_dbus_proxy_call_finish (G_DBUS_PROXY (source_object),
                                            res,
                                            &error);
-        if (result == NULL)
+        if (result == NULL &&
+            !g_error_matches (error, G_DBUS_ERROR, G_DBUS_ERROR_SERVICE_UNKNOWN))
                 g_warning ("%s: %s", msg, error->message);
 }