The help text for --init-slave=name:
"Command(s) that are executed when a slave connects to this master".
This text indicate that the --init-slave option is set on a  master 
server, and the master server passes the option's argument to slave 
which connects to it. This is wrong. Actually the --init-slave option 
just can be set on a slave server, and then the slave server executes 
the argument each time the SQL thread starts.

Correct the help text for --init-slave option as following:
"Command(s) that are executed by a slave server each time the SQL thread starts."