LU-15626 tests: Fix "error" reported by shellcheck for replay-dual

LU-15626 tests: Fix "error" reported by shellcheck for replay-dual

This patch fixes "error" issues reported by shellcheck
for file lustre/tests/replay-dual.sh. This patch also
moves spaces to tabs.

Test-Parameters: trivial testlist=replay-dual
Signed-off-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Change-Id: Ie195dd39dd4789be660115b360b5b8bf6ebc1a57
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/46835
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Jian Yu <yujian@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>