LU-15626 tests: Remove variables not used

LU-15626 tests: Remove variables not used

This patch removes variables which were
defined but not used. This was reported
by shellcheck.

This patch also replaces unicode double
quotes wherever applicable

Test-Parameters: trivial
Signed-off-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Change-Id: I996532de119806e20552e9bbe54b15615ea2c2e0
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/51499
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Timothy Day <timday@amazon.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>