scsi: qla2xxx: Save rscn_gen for new fcport

Add missing rscn_gen when creating new fcport.

Link: https://lore.kernel.org/r/20200212214436.25532-22-hmadhani@marvell.com


Signed-off-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>