tests/qtest/migration-test: Fix analyze-migration.py for s390x

The migration stream on s390x contains data for the storage_attributes
which the analyze-migration.py cannot handle yet. Add the basic code
for handling this, so we can re-enable the check in the migration-test.

Message-ID: <20231120113951.162090-1-thuth@redhat.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2 files changed