NFS check the return of nfs4_negotiate_security in nfs4_submount

Signed-off-by: Andy Adamson <andros@netapp.com>
Tested-By: Steve Dickson <steved@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

fs/nfs/nfs4namespace.c

@@ -399,7 +399,10 @@ struct vfsmount *nfs4_submount(struct nfs_server *server, struct dentry *dentry,
 		flavor = client->cl_auth->au_flavor;
 	else {
 		rpc_authflavor_t new = nfs4_negotiate_security(dir, name);
-		if ((int)new >= 0)
+		if ((int)new < 0) {
+			mnt = ERR_PTR((int)new);
+			goto out;
+		}
 		flavor = new;
 	}
 	mnt = nfs_do_submount(dentry, fh, fattr, flavor);