ocfs2: fix memory leak in ocfs2_stack_glue_init()

ocfs2_table_header should be free in ocfs2_stack_glue_init() if
ocfs2_sysfs_init() failed, otherwise kmemleak will report memleak.

BUG: memory leak
unreferenced object 0xffff88810eeb5800 (size 128):
  comm "modprobe", pid 4507, jiffies 4296182506 (age 55.888s)
  hex dump (first 32 bytes):
    c0 40 14 a0 ff ff ff ff 00 00 00 00 01 00 00 00  .@..............
    01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<000000001e59e1cd>] __register_sysctl_table+0xca/0xef0
    [<00000000c04f70f7>] 0xffffffffa0050037
    [<000000001bd12912>] do_one_initcall+0xdb/0x480
    [<0000000064f766c9>] do_init_module+0x1cf/0x680
    [<000000002ba52db0>] load_module+0x6441/0x6f20
    [<000000009772580d>] __do_sys_finit_module+0x12f/0x1c0
    [<00000000380c1f22>] do_syscall_64+0x3f/0x90
    [<000000004cf473bc>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

Link: https://lkml.kernel.org/r/41651ca1-432a-db34-eb97-d35744559de1@linux.alibaba.com
Fixes: 3878f110 ("ocfs2: Move the hb_ctl_path sysctl into the stack glue.")
Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
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>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

fs/ocfs2/stackglue.c

@@ -669,6 +669,8 @@ static struct ctl_table_header *ocfs2_table_header;
 
 static int __init ocfs2_stack_glue_init(void)
 {
+	int ret;
+
 	strcpy(cluster_stack_name, OCFS2_STACK_PLUGIN_O2CB);
 
 	ocfs2_table_header = register_sysctl("fs/ocfs2/nm", ocfs2_nm_table);
@@ -678,7 +680,11 @@ static int __init ocfs2_stack_glue_init(void)
 		return -ENOMEM; /* or something. */
 	}
 
-	return ocfs2_sysfs_init();
+	ret = ocfs2_sysfs_init();
+	if (ret)
+		unregister_sysctl_table(ocfs2_table_header);
+
+	return ret;
 }
 
 static void __exit ocfs2_stack_glue_exit(void)