mISDN: don't use flush_scheduled_work()

flush_scheduled_work() is deprecated and scheduled to be removed.
Directly flush ch->workq when freeing channel and cancel it on
release.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: netdev@vger.kernel.org
diff --git a/drivers/isdn/mISDN/hwchannel.c b/drivers/isdn/mISDN/hwchannel.c
index 307bd6e..199f374 100644
--- a/drivers/isdn/mISDN/hwchannel.c
+++ b/drivers/isdn/mISDN/hwchannel.c
@@ -110,7 +110,7 @@
 	}
 	skb_queue_purge(&ch->squeue);
 	skb_queue_purge(&ch->rqueue);
-	flush_scheduled_work();
+	flush_work_sync(&ch->workq);
 	return 0;
 }
 EXPORT_SYMBOL(mISDN_freedchannel);
@@ -143,7 +143,7 @@
 	mISDN_clear_bchannel(ch);
 	skb_queue_purge(&ch->rqueue);
 	ch->rcount = 0;
-	flush_scheduled_work();
+	flush_work_sync(&ch->workq);
 	return 0;
 }
 EXPORT_SYMBOL(mISDN_freebchannel);