vhost: fix lock on device readiness notification
vhost: fix lock on device readiness notification

The vhost notifies the application of device readiness via
vhost_user_notify_queue_state(), but calling this function
is not protected by the lock. This patch is to make this
function call lock protected.

Fixes: d0fcc38f5fa4 ("vhost: improve device readiness notifications")
Cc: stable@dpdk.org

Signed-off-by: Jiayu Hu <32e4f0527a0c8fd19a4086e4191a246becffadac@intel.com>
Reviewed-by: Maxime Coquelin <9a2667dee3b90866bbc9c2696cff2b7d5616c95a@redhat.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk