You can uninstall or removes an installed btrfs-modules-4.7.0-1-s390x-di package itself from Debian 9 (Stretch) through the terminal,
$ sudo apt-get remove btrfs-modules-4.7.0-1-s390x-di
If you would like to remove btrfs-modules-4.7.0-1-s390x-di and it's dependent packages which are no longer needed from Ubuntu,
$ sudo apt-get remove --auto-remove btrfs-modules-4.7.0-1-s390x-di
If you use with purge options to btrfs-modules-4.7.0-1-s390x-di package all the configuration and dependent packages will be removed.
$ sudo apt-get purge btrfs-modules-4.7.0-1-s390x-di
If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.
$ sudo apt-get purge --auto-remove btrfs-modules-4.7.0-1-s390x-di