docs/memory-barriers.txt/kokr: Fix style, spacing and grammar in I/O section

Translate this commit to Korean:

  0cde62a4 ("docs/memory-barriers.txt: Fix style, spacing and grammar in I/O section")

Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Link: https://lore.kernel.org/r/20191121234125.28032-4-sj38.park@gmail.com


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