sc_timepart test triggers abort in database

**Describe the bug**
sc_timepart sometimes causes the database to become unavailable. At least one of these times it was because the database aborted after [this `Pthread_mutex_lock`](https://github.com/bloomberg/comdb2/blob/main/db/osqlblockproc.c#L1353) returned EINVAL. Memory may be getting corrupted somewhere.

**To Reproduce**
Run sc_timepart