Fix "undefined reference to xdr_control" when building raidz_test cmd
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: SenH <sen@senhaerens.be>
Closes #5933