scsi/scsi_tgt_lib: scsi_tgtd isn't used in memory reclaim path

Workqueue scsi_tgtd isn't used during memory reclaim.  Convert to
alloc_workqueue() without WQ_MEM_RECLAIM.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: FUJITA Tomonori <tomof@acm.org>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: linux-scsi@vger.kernel.org

drivers/scsi/scsi_tgt_lib.c

@@ -629,7 +629,7 @@ static int __init scsi_tgt_init(void)
 	if (!scsi_tgt_cmd_cache)
 		return -ENOMEM;
 
-	scsi_tgtd = create_workqueue("scsi_tgtd");
+	scsi_tgtd = alloc_workqueue("scsi_tgtd", 0, 1);
 	if (!scsi_tgtd) {
 		err = -ENOMEM;
 		goto free_kmemcache;