ocfs2: replace deprecated simple_strtol with kstrtol

simple_strtol() ignores overflows and has an awkward interface for error
checking. Replace with the recommended kstrtol function leads to clearer
error checking and safer conversions.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Daniel Yang <[e-mail]>
Reviewed-by: Joseph Qi <[e-mail]>
Cc: Mark Fasheh <[e-mail]>
Cc: Joel Becker <[e-mail]>
Cc: Junxiao Bi <[e-mail]>
Cc: Changwei Ge <[e-mail]>
Cc: Jun Piao <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

fs/ocfs2/cluster/heartbeat.c

···
  * Copyright (C) 2004, 2005 Oracle.  All rights reserved.
  */
 
+#include "linux/kstrtox.h"
 #include <linux/kernel.h>
 #include <linux/sched.h>
 #include <linux/jiffies.h>
···
 	if (o2nm_this_node() == O2NM_MAX_NODES)
 		return -EINVAL;
 
-	fd = simple_strtol(p, &p, 0);
-	if (!p || (*p && (*p != '\n')))
+	ret = kstrtol(p, 0, &fd);
+	if (ret < 0)
 		return -EINVAL;
 
 	if (fd < 0 || fd >= INT_MAX)