illumos gate

Despite what autocorrect thinks, convert cdio(7I) to mandoc

git commit f6b3f249ec2ef9f94d38d7a7c1b4fcbe2e891933

commit  f6b3f249ec2ef9f94d38d7a7c1b4fcbe2e891933
Author: Jason King <jason.king@joyent.com>
Date:   2019-02-01T19:02:01.000Z

    9776 mandoc(1) does not support an ERRORS section for 7I man pages
    9778 Convert agpgart_io(7I) to mandoc
    9779 Convert audio(7I) to mandoc
    9780 Convert cdio(7I) to mandoc
    9777 Convert dsp(7I) to mandoc
    Reviewed by: Gergő Mihály Doma <domag02@gmail.com>
    Approved by: Richard Lowe <richlowe@richlowe.net>