features/marker: Replacing -1 with GF_CLIENT_PID_GSYNCD as part of code cleanup.

To Keep the code(rel-3.2) consistent with the master(rel-3.3) branch.

Change-Id: I6a052a35abf022d5551ec9b59db0ae19f81f326d
BUG: 769494
Signed-off-by: Mohammed Junaid <junaid@redhat.com>
Reviewed-on: http://review.gluster.org/2969
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Csaba Henk <csaba@redhat.com>