vhost: don't send RESET_OWNER at stop

vhost: don't send RESET_OWNER at stop

First of all, RESET_OWNER message is sent incorrectly, as it's sent
before GET_VRING_BASE. And the reset message would let the later call
get nothing correct.

And, sending SET_VRING_ENABLE at stop, which has already been done,
makes more sense than RESET_OWNER.

Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>