linglusterfsclient: Add fsync API
linglusterfsclient: Add fsync API

Signed-off-by: Anand V. Avati <6a1810c170bd423868ce2e225ecea39d80cade0f@amp.gluster.com>

Kaushikbv/Gluster,Kaushikbv/Gluster,Kaushikbv/Gluster