LU-14098 obdclass: try to skip corrupted llog records

LU-14098 obdclass: try to skip corrupted llog records

if llog's header or record is found corrupted, then
ignore the remaining records and try with the next one.

Lustre-commit: 910eb97c1b43a44a9da2ae14c3b83e28ca6342fc
Lustre-change: https://review.whamcloud.com/40754

Signed-off-by: Alex Zhuravlev <bzzz@whamcloud.com>
Change-Id: I86a682a8874a2184e8891ff0ee8a68414d232a79
Reviewed-on: https://review.whamcloud.com/44397
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>