EX-3750 tests: fix hot-pools and sanity-lipe merges

EX-3750 tests: fix hot-pools and sanity-lipe merges

Restore missing changes in lustre/tests/hot-pools and .../sanity-lipe.
These were not included in the lipe/ subtree merge since they were
outside that dir.

Fix hot-pools test_4 to scan the lamigo log on the MDS.
Add tests for lipe_scan2

Test-Parameters: trivial testlist=hot-pools,sanity-lipe
Fixes: 2f05a3e06928 ("EX-2453 lipe: fixup striped directory paths")
Fixes: 3eee8554c0fb ("EX-2453 lipe: add SoM handling to lipe_scan2")
Fixes: fa19bceb68e0 ("EX-1325 lamigo: improve debug/error messages")
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Change-Id: I4c34a3a8f48edf81b5231d208f1a0ff3d9a811f8
Reviewed-on: https://review.whamcloud.com/44859
Reviewed-by: Jian Yu <yujian@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>