mgmt/glusterd: Out of bounds access to fs_info struct

Change-Id: Ibc75713d35c9cbafd493c8cf6b5294eaf29f05d4
BUG: 1163920
Signed-off-by: Petr Medonos <petr.medonos@etnetera.cz>
Reviewed-on: http://review.gluster.org/9126
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>