nvme-fc: remove setting DNR on exception conditions

Current code will set DNR if the controller is deleting or there is
an error during controller init. None of this is necessary.

Remove the code that sets DNR

Signed-off-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>