mm2gv: remove open coded NULL

diff --git a/cmd/tools/mm2gv.c b/cmd/tools/mm2gv.c
index 92029900366da10707e10ab79786348e8078886e..61c14500ef4bc874414ae90b208184500479af43 100644 (file)
--- a/cmd/tools/mm2gv.c
+++ b/cmd/tools/mm2gv.c
@@ -104,9 +104,9 @@ static Agraph_t *makeDotGraph(SparseMatrix A, char *name, int dim,
     }
 
     if (SparseMatrix_known_undirected(A)) {
-       g = agopen("G", Agundirected, (Agdisc_t *) 0);
+       g = agopen("G", Agundirected, NULL);
     } else {
-       g = agopen("G", Agdirected, (Agdisc_t *) 0);
+       g = agopen("G", Agdirected, NULL);
     }
 
     if (with_val) {