minor fixes to appease pushbuild.


mysql-test/r/binlog.result:
  Bug#22540: Incorrect value in column End_log_pos of SHOW BINLOG EVENTS using InnoDB
  
  make test portable so it will work on servers with
  funny names.
mysql-test/t/binlog.test:
  Bug#22540: Incorrect value in column End_log_pos of SHOW BINLOG EVENTS using InnoDB
  
  make test portable so it will work on servers with
  funny names.
sql/log.cc:
  Bug#22540: Incorrect value in column End_log_pos of SHOW BINLOG EVENTS using InnoDB
  
  change type to uchar * so it's the same as in 5.1.