backends/cryptodev-vhost-user: Fix local_error leaks

backends/cryptodev-vhost-user: Fix local_error leaks

Do not propagate error to the upper, directly output the error
to avoid leaks.

Fixes: 2fda101de07 ("virtio-crypto: Support asynchronous mode")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2714
Signed-off-by: Gabriel Barrantes <gabriel.barrantes.dev@outlook.com>
Reviewed-by: zhenwei pi <pizhenwei@bytedance.com>
Message-Id: <DM8PR13MB50781054A4FDACE6F4FB6469B30F2@DM8PR13MB5078.namprd13.prod.outlook.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>