LU-16943 tests: fix replay-single/135 under hard failure mode

LU-16943 tests: fix replay-single/135 under hard failure mode

This patch fixes replay-single test_135() to load libcfs module
on the failover partner node to avoid 'fail_val' setting error.
It also fixes the issue that not all of the OSTs are mounted after
failing back ost1.

Lustre-change: https://review.whamcloud.com/51574
Lustre-commit: TBD (from 1b73b6465b77744992bb1f6d782362bf0cf7f409)

Test-Parameters: trivial testlist=replay-single

Test-Parameters: trivial env=FAILURE_MODE=HARD \
    clientcount=4 mdtcount=1 mdscount=2 osscount=2 \
    austeroptions=-R failover=true iscsi=1 \
    testlist=replay-single

Change-Id: Id46c722a6db9d832829a739f41f7462b32a6d9d9
Signed-off-by: Jian Yu <yujian@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/51607
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Alex Deiter <alex.deiter@gmail.com>