client_t: Fix memory leaks

        Backport of http://review.gluster.org/8247

- Assign frame->root->client so that gf_client_unref happens
  in server_connection_cleanup_flush_cbk
- Avoid taking extra ref in gf_client_get

TODO:
The whole reason why there are two types of refs
bind, ref-count is to avoid lock inside lock which
is not the case now. I will be sending one more patch
which will accomplish that as well as changing the
tablearray to list

BUG: 1116672
Change-Id: Ica87b9cbf02cae34c10789cfb56d1ccdc393cbf0
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
Reviewed-on: http://review.gluster.org/8289
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Niels de Vos <ndevos@redhat.com>