[AFS]: Implement the CB.InitCallBackState3 operation.

Implement the CB.InitCallBackState3 operation for the fileserver to
call.  This reduces the amount of network traffic because if this op
is aborted, the fileserver will then attempt an CB.InitCallBackState
operation.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc fs/afs/afs_cm.h
Simple merge

diff --cc fs/afs/cmservice.c
Simple merge