The last kernel we were using included some manual porting of the
virtio-pmem and virtio-fs patches. By moving to 5.3-rc3, we are now
closer to upstream since the virtio-pmem patches are part of the linux
kernel now. Additionally, this includes the latest patches from
virtio-fs maintainers, which works with the latest version of virtiofsd.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>