Wrong exit code when asking for help

Description:
There are weird exit codes of some utilities:

`mysql_waitpid --help` returns 255 instead of 0

`mysqladmin --help` returns 1 instead of 0

both of them accept

'--help'

(or '-?') as valid option according to the documentation

How to repeat:

$> mysql_waitpid --help &>/dev/null

$> echo $?

$> mysqladmin --help &>/dev/null

$> echo $?

Current resutls:

255

1

Expected results:

0

0