MCOL-4124 return error when COMMIT|ROLLBACK error

[davidhall586]

No description provided.

[tntnatbry]

@dhall-MariaDB

On line 520 in this file, I see the following:

        rc = ProcessCommandStatement ( thd, command, ci, schema );
        rc = ci.rc;

If ProcessCommandStatement returns a non-zero value and ci.rc=0, then we incorrectly set rc to 0.

[tntnatbry]

Also, I see one issue with the usage of rc = max(rc, rc1); if either of the two values is less than 0 (error) and the other is 0, then we incorrectly set rc to 0.