dist_util.py: use correct ID value to detect Amazon Linux 2
dist_util.py: use correct ID value to detect Amazon Linux 2

On 2d63acdd6aaf00c4c8bf979ad332776e532d2f56 we replaced 'ol' and 'amzn'
to 'oracle' and 'amazon', but distro.id() actually returns 'amzn' for
Amazon Linux 2, so we need to revert the change.

Fixes #6882

scylladb/scylla,scylladb/scylla,avikivity/scylla,avikivity/scylla,scylladb/scylla,avikivity/scylla,scylladb/scylla