nlm: use virtual ip of server to connect to client

In cases where the servers use virtual ip's, this commit
makes sure we use them and not the physical ip.

This change also refactors code around nlm4_establish_callback
by sending granted msg only after a connection establishment,
and removing the separate thread creation.

Change-Id: I087362c547a25aa52ef7fc6653845a3863466ee6
BUG: 888283
Signed-off-by: Rajesh Amaravathi <rajesh@redhat.com>
Reviewed-on: http://review.gluster.org/4326
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>