ocfs2: use the bitmap API to simplify code

Use bitmap_zero() instead of hand-writing it.  It is less verbose.

While at it, add an explicit #include <linux/bitmap.h>.

Link: https://lkml.kernel.org/r/86d2a027c319db12055c98f00c65f7d01e703722.1658436259.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

fs/ocfs2/heartbeat.c

@@ -8,6 +8,7 @@
  * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
  */
 
+#include <linux/bitmap.h>
 #include <linux/fs.h>
 #include <linux/types.h>
 #include <linux/highmem.h>
@@ -29,8 +30,7 @@
 static void ocfs2_node_map_init(struct ocfs2_node_map *map)
 {
 	map->num_nodes = OCFS2_NODE_MAP_MAX_NODES;
-	memset(map->map, 0, BITS_TO_LONGS(OCFS2_NODE_MAP_MAX_NODES) *
-	       sizeof(unsigned long));
+	bitmap_zero(map->map, OCFS2_NODE_MAP_MAX_NODES);
 }
 
 void ocfs2_init_node_maps(struct ocfs2_super *osb)