s390: don't use flush_scheduled_work()

flush_scheduled_work() is deprecated and scheduled to be removed.

* tape_3590: Create and use tape_3590_wq instead of the system_wq.

* tape_block: Directly flush requeue_task on cleanup instead of using
  flush_scheduled_work().

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
diff --git a/drivers/s390/char/tape_block.c b/drivers/s390/char/tape_block.c
index f0fa9ca..55d2d0f 100644
--- a/drivers/s390/char/tape_block.c
+++ b/drivers/s390/char/tape_block.c
@@ -264,7 +264,7 @@
 void
 tapeblock_cleanup_device(struct tape_device *device)
 {
-	flush_scheduled_work();
+	flush_work_sync(&device->blk_data.requeue_task);
 	tape_put_device(device);
 
 	if (!device->blk_data.disk) {