LU-17215 tests: sanity/398q to use $tfile

LU-17215 tests: sanity/398q to use $tfile

tfile seems to be a typo

Fixes: 43c3a804fe2 ("LU-13805 tests: Add racing tests of BIO, DIO")

Test-Parameters: trivial
Signed-off-by: Alex Zhuravlev <bzzz@whamcloud.com>
Change-Id: I85b0afce577b708ef9e69747774bd248484bd9dd
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/52772
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Mikhail Pershin <mpershin@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>