[gnome-multi-writer] Use g_set_object()

[Richard Hughes <rhughes src gnome org>]

commit f98d7cb448734e237b4a4066028e935eefe13e62
Author: Richard Hughes <richard hughsie com>
Date:   Wed Sep 23 11:31:11 2015 +0100

    Use g_set_object()

 src/gmw-device.c |    4 +---
 1 files changed, 1 insertions(+), 3 deletions(-)
---
diff --git a/src/gmw-device.c b/src/gmw-device.c
index f8c25d1..8ca46fe 100644
--- a/src/gmw-device.c
+++ b/src/gmw-device.c
@@ -374,9 +374,7 @@ gmw_device_set_udisks_block (GmwDevice *device, UDisksBlock *udisks_block)
        GmwDevicePrivate *priv = gmw_device_get_instance_private (device);
        g_return_if_fail (GMW_IS_DEVICE (device));
        g_mutex_lock (&priv->mutex);
-       if (priv->udisks_block != NULL)
-               g_object_unref (priv->udisks_block);
-       priv->udisks_block = g_object_ref (udisks_block);
+       g_set_object (&priv->udisks_block, udisks_block);
        g_mutex_unlock (&priv->mutex);
 }