Description of problem: Address post-merge review comments for commit 5784a00f997212d34bd52b2303e20c097240d91c
REVIEW: https://review.gluster.org/22537 (cluster/afr: Thin-arbiter SHD fixes) posted (#1) for review on master by Karthik U S
REVIEW: https://review.gluster.org/22537 (cluster/afr: Thin-arbiter SHD fixes) merged (#4) on master by Pranith Kumar Karampuri