lib: objagg: Use the bitmap API when applicable

Use 'bitmap_zalloc()' to simplify code, improve the semantic and reduce
some open-coded arithmetic in allocator arguments.

Also change the corresponding 'kfree()' into 'bitmap_free()' to keep
consistency.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/f9541b085ec68e573004e1be200c11c9c901181a.1640295165.git.christophe.jaillet@wanadoo.frSigned-off-by: Jakub Kicinski <kuba@kernel.org>

lib/objagg.c

@@ -781,7 +781,6 @@ static struct objagg_tmp_graph *objagg_tmp_graph_create(struct objagg *objagg)
 	struct objagg_tmp_node *node;
 	struct objagg_tmp_node *pnode;
 	struct objagg_obj *objagg_obj;
-	size_t alloc_size;
 	int i, j;
 
 	graph = kzalloc(sizeof(*graph), GFP_KERNEL);
@@ -793,9 +792,7 @@ static struct objagg_tmp_graph *objagg_tmp_graph_create(struct objagg *objagg)
 		goto err_nodes_alloc;
 	graph->nodes_count = nodes_count;
 
-	alloc_size = BITS_TO_LONGS(nodes_count * nodes_count) *
-		     sizeof(unsigned long);
-	graph->edges = kzalloc(alloc_size, GFP_KERNEL);
+	graph->edges = bitmap_zalloc(nodes_count * nodes_count, GFP_KERNEL);
 	if (!graph->edges)
 		goto err_edges_alloc;
 
@@ -833,7 +830,7 @@ static struct objagg_tmp_graph *objagg_tmp_graph_create(struct objagg *objagg)
 
 static void objagg_tmp_graph_destroy(struct objagg_tmp_graph *graph)
 {
-	kfree(graph->edges);
+	bitmap_free(graph->edges);
 	kfree(graph->nodes);
 	kfree(graph);
 }