scsi: qla2xxx: Fix wrong return value in qla_nvme_register_hba()

On an error exit path, a negative error code should be returned instead of
a positive return value.

Link: https://lore.kernel.org/r/20200802111530.5020-1-tianjia.zhang@linux.alibaba.com


Fixes: 8777e431 ("scsi: qla2xxx: Migrate NVME N2N handling into state machine")
Cc: Quinn Tran <quinn.tran@cavium.com>
Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>