scsi: libfc: don't assign resid_len in fc_lport_bsg_request

bsg_job_done takes care of updating the scsi_request structure fields.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>