glusterfsd: dump the in-memory graph rather than volfile

Currently we have been printing in the logfile, the volfile
verbatim as received from the server. However we perform
pre-processing on the graph we receive from the server, like
adding ACL translator, applying --xlator-option cli params,
etc.

So print the serialized in-memory graph as the "volfile" in
the log. This can be very handy to double check if certain
--xlator-option param actually got applied or not, and in
general is showing a "truer" representation of the real graph
actually used.

Change-Id: I0221dc56e21111b48a1ee3e5fe17a5ef820dc0c6
BUG: 924504
Signed-off-by: Anand Avati <avati@redhat.com>
Reviewed-on: http://review.gluster.org/4708
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Amar Tumballi <amarts@redhat.com>