Summary:
When prefix_size = -1, stress test crashes with run time error because of overflow. Fix it by not using -1 but 7 in prefix scan mode.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5862
Test Plan:
Run
python -u tools/db_crashtest.py --simple whitebox --random_kill_odd \
888887 --compression_type=zstd
and see it doesn't crash.
Differential Revision: D17642313
fbshipit-source-id: f029e7651498c905af1b1bee6d310ae50cdcda41