extras/hook-scripts: Enable per client logging for gluster shares served by SAMBA

Edited hook scrips to add a variable in the option 'log file', which will be
substituted for client IP.

Change-Id: I50f143bb3114eb00afab2e1237d749804c885ca6
BUG: 1020848
Signed-off-by: Poornima <pgurusid@redhat.com>
Reviewed-on: http://review.gluster.org/6109
Reviewed-by: Niels de Vos <ndevos@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>