tests, profiles: Use IEC prefixes for binary multiples

tests, profiles: Use IEC prefixes for binary multiples

Use IEC 80000-13 prefixes for binary multiples of bytes
(KiB, MiB, etc.) rather than SI prefixes for decimal multiples
of bytes (KB, MB, etc.) in places in which the code has fixed
divide by 1024, 1024*1024, >>20, etc.  and is clearly always
using binary multiples.

Signed-off-by: Jens Axboe <axboe@fb.com>