LU-8364 ldiskfs: fixes for failover mode for RHEL7.3

LU-8364 ldiskfs: fixes for failover mode for RHEL7.3

When ldiskfs runs in failover mode with read-only disk, it
may lose part of allocation updates and fail while mounting
fs due to group descriptor checks before journal replay.
Don't produce panics with on-disk checks in read-only mode.

Include ext4-dont-check-before-replay and ext4-dont-check-in-ro
patches in the RHEL7.3 series.

The check-ro patch should be ported in to RHEL7.3.

Signed-off-by: Yang Sheng <yang.sheng@intel.com>
Change-Id: Icd4b899f9c48040c2453c4d759149e323fa33e18
Reviewed-on: https://review.whamcloud.com/27077
Tested-by: Jenkins
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>