Affects:
MDEV-34150 Assertion failure in Diagnostics_area::set_error_status upon binary
           logging hitting tmp space limit
MDEV-9101 Limit size of created disk temporary files and tables

This bug was caused by moving flushing of the in-memory-row-events from
close_thread_tables() to binlog_commit() in MDEV-34150.
This was needed to be able to handle the case where binlog writes could
fail.

Galera have two case where the change caused problems:

- Row events in commit_one_phase_2() was not done in the case the standard
  binary log was not enabled but Galera was using the binary log
  internally.
- Galera disabled the call to binlog_commit_flush_stmt_cache() for not
  ending transactions.

Fixed by adding code that flushes the in-memory-row-events to the binary
log (write, but now sync) in the two above cases if Galera is enabled.