ocfs2: o2hb: revert hb threshold to keep compatible

Configfs is the interface for ocfs2-tools to set configure to kernel and
$configfs_dir/cluster/$clustername/heartbeat/dead_threshold is the one
used to configure heartbeat dead threshold.  Kernel has a default value
of it but user can set O2CB_HEARTBEAT_THRESHOLD in /etc/sysconfig/o2cb
to override it.

Commit 45b997737a80 ("ocfs2/cluster: use per-attribute show and store
methods") changed heartbeat dead threshold name while ocfs2-tools did
not, so ocfs2-tools won't set this configurable and the default value is
always used.  So revert it.

Fixes: 45b997737a80 ("ocfs2/cluster: use per-attribute show and store methods")
Link: http://lkml.kernel.org/r/1490665245-15374-1-git-send-email-junxiao.bi@oracle.com
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Acked-by: Joseph Qi <jiangqi903@gmail.com>
Cc: Mark Fasheh <mfasheh@versity.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/ocfs2/cluster/heartbeat.c

@@ -2242,13 +2242,13 @@ unlock:
 	spin_unlock(&o2hb_live_lock);
 }
 
-static ssize_t o2hb_heartbeat_group_threshold_show(struct config_item *item,
+static ssize_t o2hb_heartbeat_group_dead_threshold_show(struct config_item *item,
 		char *page)
 {
 	return sprintf(page, "%u\n", o2hb_dead_threshold);
 }
 
-static ssize_t o2hb_heartbeat_group_threshold_store(struct config_item *item,
+static ssize_t o2hb_heartbeat_group_dead_threshold_store(struct config_item *item,
 		const char *page, size_t count)
 {
 	unsigned long tmp;
@@ -2297,11 +2297,11 @@ static ssize_t o2hb_heartbeat_group_mode_store(struct config_item *item,
 
 }
 
-CONFIGFS_ATTR(o2hb_heartbeat_group_, threshold);
+CONFIGFS_ATTR(o2hb_heartbeat_group_, dead_threshold);
 CONFIGFS_ATTR(o2hb_heartbeat_group_, mode);
 
 static struct configfs_attribute *o2hb_heartbeat_group_attrs[] = {
-	&o2hb_heartbeat_group_attr_threshold,
+	&o2hb_heartbeat_group_attr_dead_threshold,
 	&o2hb_heartbeat_group_attr_mode,
 	NULL,
 };