When destroy qos, spdk_bdev_qos_destroy() allocates a new qos, and swap
old one. After spdk_bdev_unregister() frees the new qos, the old qos poller
may still reference new qos via bdev->internal.qos. Fix this error by
using old qos in _spdk_bdev_qos_io_submit().
Reported in 72aac51430.1539054028/ubuntu16.04/build.log
Change-Id: Id1bce6c8b1cefae604dd2c69e8f3482ec34b1b54
Signed-off-by: wuzhouhui <wuzhouhui@kingsoft.com>
Reviewed-on: https://review.gerrithub.io/428444
Chandler-Test-Pool: SPDK Automated Test System <sys_sgsw@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
3785a4d83b