LU-13535 lfsck: fix possible PFL layout corruption

LU-13535 lfsck: fix possible PFL layout corruption

While checking lmm_oi in composite layout the pointer to 'lmm'
is re-assigned to component entry but the same pointer is used
for LOV EA buffer to update EA. Therefore if lmm_oi was fixed in
some component then just current entry is saved as new layout.

Lustre-change: https://review.whamcloud.com/38584
Lustre-commit: be009cb4a73b3bef7302083bec7d1d6289d515b7

Signed-off-by: Mikhail Pershin <mpershin@whamcloud.com>
Change-Id: Ifbd984a71b383ab4ca35ad59ed9cd8cf57b6d7cc
Reviewed-on: https://review.whamcloud.com/38585
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Stephan Thiell <sthiell@stanford.edu>