docs/memory-barriers.txt/kokr: Remove remaining references to mmiowb()

Translate this commit to Korean:

    a897b13d ("docs/memory-barriers.txt: Remove remaining references to mmiowb()")

Signed-off-by: SeongJae Park <sjpark@amazon.de>
Reviewed-by: Yunjae Lee <lyj7694@gmail.com>
Link: https://lore.kernel.org/r/20200829082607.3146-3-sj38.park@gmail.com


Signed-off-by: Jonathan Corbet <corbet@lwn.net>