Kernel warning on reboot: "waiting module removal not supported: please upgrade"

Description of problem:
Kernel warning on reboot
How reproducible:
Reboot host
>Actual results:
form /var/log/messages
May 30 08:17:01 hostname kernel: [343982.373189] CT: 105: checkpointed
May 30 08:17:01 hostname kernel: [343982.392883] CPT ERR: Can't find ip6tables-save, ignoring...
May 30 08:17:01 hostname kernel: [343982.457982] CT: 117: checkpointed
May 30 08:17:02 hostname kernel: [343983.170831] CT: 103: checkpointed
May 30 08:17:02 hostname kernel: [343983.172282] CT: 105: stopped
May 30 08:17:02 hostname kernel: [343983.269372] CT: 117: stopped
May 30 08:17:02 hostname kernel: [343983.367511] CT: 103: stopped
May 30 08:17:07 hostname kernel: [343988.713678] waiting module removal not supported: please upgrade
May 30 08:17:07 hostname kernel: [343988.747742] waiting module removal not supported: please upgrade
May 30 08:17:07 hostname kernel: [343988.756464] waiting module removal not supported: please upgrade
May 30 08:17:07 hostname kernel: [343988.767705] waiting module removal not supported: please upgrade
May 30 08:17:07 hostname kernel: [343988.767948] waiting module removal not supported: please upgrade
May 30 08:17:07 hostname kernel: [343988.768112] waiting module removal not supported: please upgrade
May 30 08:17:07 hostname kernel: [343988.783839] waiting module removal not supported: please upgrade
May 30 08:17:07 hostname kernel: [343988.787159] waiting module removal not supported: please upgrade
May 30 08:17:07 hostname kernel: [343988.790757] waiting module removal not supported: please upgrade
May 30 08:17:07 hostname kernel: [343988.791579] waiting module removal not supported: please upgrade
May 30 08:17:07 hostname kernel: [343988.792416] waiting module removal not supported: please upgrade
May 30 08:17:07 hostname kernel: [343988.793235] waiting module removal not supported: please upgrade
May 30 08:17:08 hostname kernel: [343988.796548] waiting module removal not supported: please upgrade
May 30 08:17:08 hostname kernel: [343988.842517] waiting module removal not supported: please upgrade
May 30 08:17:08 hostname kernel: [343988.844100] waiting module removal not supported: please upgrade
May 30 08:17:08 hostname kernel: [343988.844940] waiting module removal not supported: please upgrade
May 30 08:17:08 hostname kernel: [343988.845793] waiting module removal not supported: please upgrade
May 30 08:17:08 hostname kernel: [343988.857104] waiting module removal not supported: please upgrade
May 30 08:17:08 hostname kernel: [343988.857375] waiting module removal not supported: please upgrade
May 30 08:17:08 hostname kernel: [343988.857468] FS-Cache: Netfs 'nfs' unregistered from caching
May 30 08:17:08 hostname kernel: [343988.857656] waiting module removal not supported: please upgrade
May 30 08:17:08 hostname kernel: [343988.857795] waiting module removal not supported: please upgrade
May 30 08:17:08 hostname kernel: [343988.857841] Slow work thread pool: Shutting down
May 30 08:17:08 hostname kernel: [343988.857871] Slow work thread pool: Shut down complete
May 30 08:17:08 hostname kernel: [343988.857889] FS-Cache: Unloaded
May 30 08:17:08 hostname kernel: [343988.858015] waiting module removal not supported: please upgrade
May 30 08:17:08 hostname kernel: [343988.866990] waiting module removal not supported: please upgrade
May 30 08:17:08 hostname kernel: [343988.869271] waiting module removal not supported: please upgrade
May 30 08:17:08 hostname kernel: [343988.869332] RPC: Unregistered named UNIX socket transport module.
May 30 08:17:08 hostname kernel: [343988.869350] RPC: Unregistered udp transport module.
May 30 08:17:08 hostname kernel: [343988.869364] RPC: Unregistered tcp transport module.
May 30 08:17:08 hostname kernel: [343988.869377] RPC: Unregistered tcp NFSv4.1 backchannel transport module.
May 30 08:17:08 hostname kernel: [343988.878189] waiting module removal not supported: please upgrade
>Expected results:
No warning
>Host OS:
CentOS 6.8
>Guest OS:
N/A (CentOS 6.8/Debian testing)
>Additional info (see https://openvz.org/Reporting_OpenVZ_problem):
 uname -a
Linux hostname 2.6.32-042stab116.1 #1 SMP Wed May 4 16:21:02 MSK 2016 x86_64 x86_64 x86_64 GNU/Linux
vzctl --version
vzctl version 4.9.4

Similar to
https://forum.proxmox.com/threads/porxmox-3-4-kernel-waiting-module-removal-not-supported-please-upgrade.22041/