nvme-fc: fix initialization order

ctrl->ops is used by nvme_alloc_admin_tag_set() but set by
nvme_init_ctrl() so reorder the calls to avoid a NULL pointer
dereference.

Fixes: 6dfba1c0 ("nvme-fc: use the tagset alloc/free helpers")
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>