Currently, when host set VF untrusted, the driver will disable
the promisc mode of VF. It may be conflicted when the VF requests
the host to set promisc mode. So refactor it by changing promisc
mode for VF asynchronously. With this change, the promisc mode of
VF can be restored when the VF being trusted again.

Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>