When hotplug ovs kernel netcard, even tap TUNGETIFF failed,
the hotplug would go on and would lead to qemu assert.
The failure should lead to the free_fail.
Signed-off-by: miaoyubo <miaoyubo@huawei.com>
Signed-off-by: Yan Wang <wangyan122@huawei.com>
Signed-off-by: imxcc <xingchaochao@huawei.com>
(cherry picked from commit fcfc664bacbb7d51d667dd6d0c20ce088bc7effe)
