LU-16275 tests: Modify killall of replay-dual 25

LU-16275 tests: Modify killall of replay-dual 25

The in-tree test will have rename the multiop to lt-multiop,
which will not be killed with killall. So it's better to add
regex to killall for kill all the process with multiop and
lt-multiop

Test-Parameters: trivial testlist=replay-dual env=ONLY=25
Signed-off-by: Kevin Zhao <kevin.zhao@linaro.org>
Change-Id: Ic9b064a6bb0d944eedb5dc019ba5d4d05c98eeae
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/48977
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Vitaliy Kuznetsov <vkuznetsov@ddn.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>