cluster/afr: Fix dict_t leaks

        Backport of: http://review.gluster.org/#/c/8557/

dict_t objects that are ref'd in alloca'd "replies" in
afr_replies_copy() are not unref'd before "replies" go out of scope.

Change-Id: I9bb45bc673ec13292ac96dda060aceb48739ebe8
BUG: 1136831
Signed-off-by: Krutika Dhananjay <kdhananj@redhat.com>
Reviewed-on: http://review.gluster.org/8704
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>