LU-18214 tests: modify test_5{a,b,c,d} for parallel

LU-18214 tests: modify test_5{a,b,c,d} for parallel

In order to measure the lock performance under contention
case. Modify the test_5x to run on multi clients.

Test-Parameters: trivial testlist=performance-sanity env=ONLY=5
Signed-off-by: Yang Sheng <ys@whamcloud.com>
Change-Id: I75b723504d569253ca3e54ad363faeceb5d49e5c
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/57060
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>