innobackupex --slave-info report a single "m" instead of "slave info" in std output.

[jixiangqd]

Version: xtrabackup 2.4.8

I found it in

storage/innobase/xtrabackup/src/backup_mysql.cc 1388:1391
```
  if (tmp_mysql_slave_position) {
   mysql_slave_position += '\n';
   mysql_slave_position += *tmp_mysql_slave_position;
  }
```

while tmp_mysql_slave_position is typeof "char *", so that it extract "tmp_mysql_slave_position"'s first char "m" and added into output str "mysql_slave_position".
And the line 1389 is not necessary here, while earlier version's output infos inline.

this problem will fixed easy with this patch(tested):

```
  if (tmp_mysql_slave_position) {
   mysql_slave_position += tmp_mysql_slave_position;
  }
```

Thanks you guys.

[Sergei Glushchenko (sergei.glushchenko)]

This has been fixed in this commit https://github.com/percona/percona-xtrabackup/commit/7605e5673cb560a7115a983f3acdcec6d5d6fdee

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PXB-510