scsi: libfc: Replace ->seq_set_resp callback with direct function call

The ->seq_set_resp callback only ever had one implementation,
so call it directly and drop the callback.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>