scsi: fcoe: Simplify the return expression of fcoe_sysfs_setup()

Simplify the return expression.

Link: https://lore.kernel.org/r/20200921131102.93084-1-miaoqinglang@huawei.com
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>