LU-15495 tests: fixed dbench test

LU-15495 tests: fixed dbench test

* Using awk to get list shared libraries
* Fixed shellcheck warnings

Lustre-change: https://review.whamcloud.com/49088
Lustre-commit: 01fb7bda971ee9d5dcd3950f40668131f306b8c5

Test-Parameters: trivial testlist=sanity \
clientdistro=el7.9 clientarch=x86_64 \
env=SLOW=yes,ONLY=71

Test-Parameters: trivial testlist=sanity \
clientdistro=el8.7 clientarch=x86_64 \
env=SLOW=yes,ONLY=71

Test-Parameters: trivial testlist=sanity \
clientdistro=el8.7 clientarch=aarch64 \
env=SLOW=yes,ONLY=71

Test-Parameters: trivial testlist=sanity \
clientdistro=el8.7 clientarch=ppc64le \
env=SLOW=yes,ONLY=71

Test-Parameters: trivial testlist=sanity \
clientdistro=el9.0 clientarch=x86_64 \
env=SLOW=yes,ONLY=71

Test-Parameters: trivial testlist=sanity \
clientdistro=sles12sp5 clientarch=x86_64 \
env=SLOW=yes,ONLY=71

Test-Parameters: trivial testlist=sanity \
clientdistro=sles15sp4 clientarch=x86_64 \
env=SLOW=yes,ONLY=71

Test-Parameters: trivial testlist=sanity \
clientdistro=ubuntu2004 clientarch=x86_64 \
env=SLOW=yes,ONLY=71

Test-Parameters: trivial env=SLOW=yes,ONLY=26 testlist=replay-dual

Test-Parameters: trivial env=SLOW=yes,ONLY=70b testlist=replay-single

Test-Parameters: trivial env=SLOW=yes,ONLY=8 testlist=sanity-pfl

Test-Parameters: trivial env=SLOW=yes,ENABLE_QUOTA=yes,ONLY=8 \
testlist=sanity-quota

Signed-off-by: Alex Deiter <alex.deiter@gmail.com>
Change-Id: Ic28bd67dcfb5ff24e65e33278ac867409a2c1cc6
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/51284
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>