qemuDomainObjPrivateFree: Free @machineName

We're storing the machine name in @priv but free it just in
qemuProcessStop, Therefore this may leak.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

src/qemu/qemu_domain.c

@@ -1722,6 +1722,7 @@ qemuDomainObjPrivateFree(void *data)
     virBitmapFree(priv->autoNodeset);
     virBitmapFree(priv->autoCpuset);
 
+    VIR_FREE(priv->machineName);
     VIR_FREE(priv->libDir);
     VIR_FREE(priv->channelTargetDir);