[debian-mysql] Mariadb 10.3 RocksDB testsuite fix for s390x

[Otto Kekäläinen]

Hello!

Please pick the one you think is best and open a "pull request" at
https://salsa.debian.org/mariadb-team/mariadb-10.3/merge_requests (see
https://wiki.debian.org/Teams/MySQL/patches).

During the upload process I always do test builds at
https://launchpad.net/~mysql-ubuntu/+archive/ubuntu/mariadb-10.3/+builds?build_text=&build_state=all
but that does not cover autopkgtests, and the CI pipeline on Salsa
that includes autopkgtests does not include s390x...