scsi: NCR5380: Use default @max_active for hostdata->work_q

hostdata->work_q only hosts a single work item, hostdata->main_task, and
thus doesn't need explicit concurrency limit. Let's use the default
@max_active. This doesn't cost anything and clearly expresses that
@max_active doesn't matter.

Signed-off-by: Tejun Heo <[e-mail]>
Acked-by: Finn Thain <[e-mail]>
Acked-by: "Martin K. Petersen" <[e-mail]>
Cc: Michael Schmitz <[e-mail]>
Cc: "James E.J. Bottomley" <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]

drivers/scsi/NCR5380.c

···
 	INIT_WORK(&hostdata->main_task, NCR5380_main);
 	hostdata->work_q = alloc_workqueue("ncr5380_%d",
 	                        WQ_UNBOUND | WQ_MEM_RECLAIM,
-	                        1, instance->host_no);
+				0, instance->host_no);
 	if (!hostdata->work_q)
 		return -ENOMEM;