LU-18325 tests: sanity 842: load_module ldlm_extent failed

LU-18325 tests: sanity 842: load_module ldlm_extent failed

Skip the MDS without ldlm_extent module.

Test-Parameters: trivial testlist=sanity
Signed-off-by: Yang Sheng <ys@whamcloud.com>
Change-Id: I9d1ec659088b7314ee3ae2fb09fc49ee3ef5a922
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/56630
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>