vdpa net: stop probing if cannot set features

Otherwise it continues the CVQ isolation probing.

Fixes: 152128d ("vdpa: move CVQ isolation check to net_init_vhost_vdpa")
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Message-Id: <20230915170836.3078172-3-eperezma@redhat.com>
Tested-by: Lei Yang <leiyang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

net/vhost-vdpa.c

@@ -1364,6 +1364,7 @@ static int vhost_vdpa_probe_cvq_isolation(int device_fd, uint64_t features,
     r = ioctl(device_fd, VHOST_SET_FEATURES, &features);
     if (unlikely(r)) {
         error_setg_errno(errp, errno, "Cannot set features");
+        goto out;
     }
 
     r = ioctl(device_fd, VHOST_VDPA_SET_STATUS, &status);