scsi: hisi_sas: Fix out of bound at debug_I_T_nexus_reset()

Fix a possible out-of-bounds access in hisi_sas_debug_I_T_nexus_reset().

Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>