NFS : Volume access option accepts only valid values.
NFS : Volume access option accepts only valid values.

Signed-off-by: Gaurav <gaurav@gluster.com>
Signed-off-by: Vijay Bellur <vijay@dev.gluster.com>

BUG: 2598 (Volume access option suceeds with any string value)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=2598

Kaushikbv/Gluster,Kaushikbv/Gluster,Kaushikbv/Gluster