test: test re-opens of open-fds

Change-Id: Ic99c7f3cf1f6a381b0fc1b2ca1acc19f5fe75523
BUG: 821056
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
Reviewed-on: http://review.gluster.org/4387
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>