scsi: scsi_transport_fc: Add a new rport state FC_PORTSTATE_MARGINAL

scsi: scsi_transport_fc: Add a new rport state FC_PORTSTATE_MARGINAL

Add a new interface, fc_eh_should_retry_cmd(), which checks if the cmd
should be retried or not by checking the rport state. If the rport state is
marginal it returns false to make sure there won't be any retries on the
cmd.

Make the fc_remote_port_delete(), fc_user_scan_tgt(), and
fc_timeout_deleted_rport() functions handle the new rport state.

Link: https://lore.kernel.org/r/1609969748-17684-4-git-send-email-muneendra.kumar@broadcom.com
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Muneendra Kumar <muneendra.kumar@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>