LU-18293 tests: Revert "LU-18293 test: use direct IO for"

LU-18293 tests: Revert "LU-18293 test: use direct IO for"

This reverts commit 2f96622a522924c7b9e26fd2dfdf34eb6227b7a6
as it causes many failures in sanity-quota/71a

Signed-off-by: Alex Zhuravlev <bzzz@whamcloud.com>
Change-Id: I94d5ca67db64c0eead079ae415455f9c5951f9ed
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/58790
Reviewed-by: Sebastien Buisson <sbuisson@ddn.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>