arm64/mpam: fix device_errcode out of bounds

kylin inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4AHUH?from=project-issue
CVE: NA

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the size of mpam_msc_err_str is _MPAM_NUM_ERRCODE,
so device_errcode needs to be less than _MPAM_NUM_ERRCODE.
Signed-off-by: Nyin-xiujiang <yinxiujiang@kylinos.cn>
Reviewed-by: Jian Cheng <cj.chengjian(a)huawei.com>
Signed-off-by: NWang ShaoBo <bobo.shaobowang@huawei.com>

arch/arm64/kernel/mpam/mpam_device.c

@@ -435,7 +435,7 @@ static irqreturn_t mpam_handle_error_irq(int irq, void *data)
 		return IRQ_NONE;
 
 	/* No-one expects MPAM errors! */
-	if (device_errcode <= _MPAM_NUM_ERRCODE)
+	if (device_errcode < _MPAM_NUM_ERRCODE)
 		pr_err_ratelimited("unexpected error '%s' [esr:%x]\n",
 					mpam_msc_err_str[device_errcode],
 					device_esr);