The vring relay thread is created after HW datapath start and is
canceled before HW datapath stop, so we need to take care of the
ring update when the relay thread is not on duty.
Fixes: 4bb531e152d3 ("net/ifc: support SW assisted VDPA live migration")
Cc: stable@dpdk.org
Signed-off-by: Xiao Wang <xiao.w.wang@intel.com>
9cdbd048ca