NFS do not find client in NFSv4 pg_authenticate

The information required to find the nfs_client cooresponding to the incoming
back channel request is contained in the NFS layer. Perform minimal checking
in the RPC layer pg_authenticate method, and push more detailed checking into
the NFS layer where the nfs_client can be found.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index 4bb91cb..829f406 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -373,17 +373,11 @@
 {
 	struct nfs_client *clp;
 	int i;
-	__be32 status;
+	__be32 status = htonl(NFS4ERR_BADSESSION);
 
 	cps->clp = NULL;
 
-	status = htonl(NFS4ERR_BADSESSION);
-	/* Incoming session must match the callback session */
-	if (memcmp(&args->csa_sessionid, cps->svc_sid, NFS4_MAX_SESSIONID_LEN))
-		goto out;
-
-	clp = nfs4_find_client_sessionid(args->csa_addr,
-					 &args->csa_sessionid, 1);
+	clp = nfs4_find_client_sessionid(args->csa_addr, &args->csa_sessionid);
 	if (clp == NULL)
 		goto out;