vhost_net.c: v2 Fix build failure introduced by 0bfcd599

Fix build failure introduced by 0bfcd599

The format statement expects unsigned long on x86_64, but receives
unsigned long long, so gcc exits with an error.
Signed-off-by: NJes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

hw/vhost_net.c

@@ -100,7 +100,7 @@ struct vhost_net *vhost_net_init(VLANClientState *backend, int devfd)
     }
     if (~net->dev.features & net->dev.backend_features) {
         fprintf(stderr, "vhost lacks feature mask %" PRIu64 " for backend\n",
-                ~net->dev.features & net->dev.backend_features);
+                (uint64_t)(~net->dev.features & net->dev.backend_features));
         vhost_dev_cleanup(&net->dev);
         goto fail;
     }