nvme-fc: don't override opts->nr_io_queues

Its what the user passed, so its probably a better
idea to keep it intact. Also, limit the number of
I/O queues to max online cpus and the lport maximum
hw queues.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>