um: virtio_uml: fix memory leak on init failures

um: virtio_uml: fix memory leak on init failures

commit 7ad28e0df7ee9dbcb793bb88dd81d4d22bb9a10e upstream.

If initialization fails, e.g. because the connection failed,
we leak the 'vu_dev'. Fix that. Reported by smatch.

Fixes: a27e1c429147 ("um: drivers: Add virtio vhost-user driver")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>