LU-15421 tests: Add missing error() calls on errors

LU-15421 tests: Add missing error() calls on errors

Just a quoted string does not really do what we need

Fixes: 8befc64e5a ("LU-13404 utils: fix lfs mirror duplicate file check")
Fixes: 41bfc1ec78 ("LU-8998 tests: test scripts for PFL")
Fixes: 3afede2b81 ("LU-8900 snapshot: user interface for write barrier on MDT")
Fixes: fdad38781c ("LU-11376 lmv: new foreign LMV format")
Fixes: 6a20bdcc60 ("LU-11376 lov: new foreign LOV format")
Fixes: 4af3ab1945 ("LU-2017 mdc: add layout swap between 2 objects")
Test-Parameters: trivial testlist=sanity,sanity-pfl,sanity-flr,sanity-lfsck
Change-Id: Id0f70512ade1cc93cbd4979dc2925f1e834f6816
Signed-off-by: Oleg Drokin <green@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/45995
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: James Nunez <jnunez@whamcloud.com>