NFS : Coverity Fix.

NFS defects reported by  Coverity run are fixed.

Change-Id: Ib66847e8e66fb4a06b312c80814f9eafb032eba2
BUG: 996390
Signed-off-by: meghana <mmadhusu@redhat.com>
Reviewed-on: http://review.gluster.org/5660
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Varun Shastry <vshastry@redhat.com>
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>