MDEV-35528: mariadb-binlog cannot process more than 1 logfiles when --stop-datetime...

MDEV-35528: mariadb-binlog cannot process more than 1 logfiles when --stop-datetime is specified

Fix regression introduced by commits 9588526 and 242b67f which attempted to
address MDEV-27037. With the regression, mariadb-binlog cannot process multiple
log files when --stop-datetime is specified.

Remove the code to set retval as OK_STOP if mariadb-binlog finished processing
current log file but not reached specified --stop-datetime or --stop-position,
to make it possible to continue process following log files.

All new code of the whole pull request, including one or several files that are
either new files or modified ones, are contributed under the BSD-new license. I
am contributing on behalf of my employer Amazon Web Services, Inc.

Forwarded: https://github.com/MariaDB/server/pull/3670
Origin: https://patch-diff.githubusercontent.com/raw/MariaDB/server/pull/3670.patch

Gbp-Pq: Name MDEV-35528-mariadb-binlog-cannot-process-more-than-1-logf.patch