fix qemu 2.9 drive mirroring to nbd target

fix qemu 2.9 drive mirroring to nbd target

cherry pick from qemu-kvm-ev-2.9.0-16.el7_4.11.1
https://cbs.centos.org/koji/buildinfo?buildID=21003

Tue Jun 13 2017 Miroslav Rezanina <mrezanin@redhat.com> - rhev-2.9.0-10.el7

- kvm-nbd-make-it-thread-safe-fix-qcow2-over-nbd.patch [bz#1454582]

Tue Aug 15 2017 Miroslav Rezanina <mrezanin@redhat.com> - rhev-2.9.0-16.el7_4.4
- kvm-nbd-strict-nbd_wr_syncv.patch [bz#1467509]
- kvm-nbd-read_sync-and-friends-return-0-on-success.patch [bz#1467509]
- kvm-nbd-make-nbd_drop-public.patch [bz#1467509]
- kvm-nbd-server-get-rid-of-nbd_negotiate_read-and-friends.patch [bz#1467509]

Mon Oct 09 2017 Miroslav Rezanina <mrezanin@redhat.com> - rhev-2.9.0-16.el7_4.9
- kvm-nbd-client-Fix-regression-when-server-sends-garbage.patch [bz#1495474]
- kvm-fix-build-failure-in-nbd_read_reply_entry.patch [bz#1495474]
- kvm-nbd-client-avoid-spurious-qio_channel_yield-re-entry.patch [bz#1495474]
- kvm-nbd-client-avoid-read_reply_co-entry-if-send-failed.patch [bz#1495474]
- kvm-qemu-iotests-improve-nbd-fault-injector.py-startup-p.patch [bz#1495474]
- kvm-qemu-iotests-test-NBD-over-UNIX-domain-sockets-in-08.patch [bz#1495474]
- kvm-block-nbd-client-nbd_co_send_request-fix-return-code.patch [bz#1495474]
- Resolves: bz#1495474