Cluster service with nfsserver resource fails to stop with "[nfsserver] Failed: umount /var/lib/nfs/statd" in RHEL 6

Issue

• We configured an NFS service in our clustercluster. When NFS service is relocated, it fails to umount /var/lib/nfs/statd and it stops the NFS
  service.
• The nfsserver resource in our cluster service fails to stop on unmounting /var/lib/nfs/statd:

Apr 15 02:07:48 hostname1 [nfsserver] Stopping NFS daemons
Apr 15 02:07:48 hostname1 [nfsserver] NFS daemons are stopped
Apr 15 02:07:48 hostname1 [nfsserver] Copying sm files for future notification...
Apr 15 02:07:49 hostname1 [nfsserver] Stopping rpc.statd
Apr 15 02:07:50 hostname1 [nfsserver] rpc.statd is stopped
Apr 15 02:07:50 hostname1 [nfsserver] umount /var/lib/nfs/statd
Apr 15 02:07:50 hostname1 [nfsserver] Failed: umount /var/lib/nfs/statd
Apr 15 02:07:50 hostname1 stop on nfsserver "NFS" returned 1 (generic error)
Apr 15 02:07:50 hostname1 [ip] Removing IPv4 address X.X.X.X/Y from bond0
Apr 15 02:08:10 hostname1 #12: RG service:NFS-service failed to stop; intervention required
Apr 15 02:08:10 hostname1 Service service:NFS-service is failed