staging: wlan-ng: Remove flush_scheduled_work

flush_scheduled_work() is scheduled for deprecation. Use
cancel_work_sync() instead to ensure that there is no pending or
running work item.
Signed-off-by: NAmitoj Kaur Chawla <amitoj1606@gmail.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wlan-ng/prism2usb.c

@@ -177,7 +177,8 @@ static void prism2sta_disconnect_usb(struct usb_interface *interface)
 		tasklet_kill(&hw->completion_bh);
 		tasklet_kill(&hw->reaper_bh);
 
-		flush_scheduled_work();
+		cancel_work_sync(&hw->link_bh);
+		cancel_work_sync(&hw->commsqual_bh);
 
 		/* Now we complete any outstanding commands
 		 * and tell everyone who is waiting for their