nvme/fc: simplify error handling of nvme_fc_create_hw_io_queues

Simplify the error handling of nvme_fc_create_hw_io_queues(), this saves us
one variable and one level of indentation.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviwed-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>