LU-15156 kernel: back port patch for rwsem issue

LU-15156 kernel: back port patch for rwsem issue

RHEL7 included a defect in rwsem. It can cause a
thread hung on rwsem waiting infinity. Backport
commit: 5c1ec49b60cdb31e51010f8a647f3189b774bddf
to fix this issue.

Lustre-commit: 85362faed8f5ee94ffee1f3f6330beee57ea9284
Lustre-change: https://review.whamcloud.com/45383

Signed-off-by: Yang Sheng <ys@whamcloud.com>
Change-Id: Ic5c469ce744ad5882c13163a9bfe14faef8fd446
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Alex Zhuravlev <bzzz@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/46041
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>