arm64/mpam: fix compile warning

hulk inclusion
category: bugfix
bugzilla: 48265
CVE: NA

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Fix the compile warning
fs/resctrlfs.c: In function ‘resctrl_mount’:
fs/resctrlfs.c:358:1: warning: label ‘out_mongrp’ defined but not used [-Wunused-label]
 out_mongrp:

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Wang ShaoBo <bobo.shaobowang@huawei.com>
Reviewed-by: Cheng Jian <cj.chengjian@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>