NFSv4: It's perfectly legal for clp to be NULL here....

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 110f80e..ec1938d 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -269,7 +269,7 @@
 	clp = __nfs_find_client(addr, nfsversion);
 	spin_unlock(&nfs_client_lock);
 
-	BUG_ON(clp->cl_cons_state == 0);
+	BUG_ON(clp && clp->cl_cons_state == 0);
 
 	return clp;
 }