Fix check of parameter type in mysqld_start.

  {

    $exe= $exe_master_mysqld;

  }

  if ( $type eq 'slave' )

  elsif ( $type eq 'slave' )

  {

    $exe= $exe_slave_mysqld;

  }

  else

  {

    mtr_error("Unknown 'type' passed to mysqld_start");

    mtr_error("Unknown 'type' \"$type\" passed to mysqld_start");

  }

  mtr_init_args(\$args);