NFSv4.1: There is no need to init the session more than once...

Set up a flag to ensure that is indeed the case.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 04eff16..a986f13 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -49,6 +49,7 @@
 };
 
 enum nfs4_session_state {
+	NFS4_SESSION_INITING,
 	NFS4_SESSION_DRAINING,
 };