LU-15626 tests: Fix "error" reported by shellcheck (4/5)

LU-15626 tests: Fix "error" reported by shellcheck (4/5)

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

Signed-off-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Change-Id: I84b43cba5b50d6618bee756d2f3c7f59ab0d74da
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/49438
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Jian Yu <yujian@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>