usb: don't use flush_scheduled_work()

flush_scheduled_work() is being deprecated.  Directly flush or cancel
work items instead.

* u_ether, isp1301_omap, speedtch conversions are straight-forward.

* ochi-hcd should only flush when quirk_nec() is true as otherwise the
  work wouldn't have been initialized.

* In oti6858, cancel_delayed_work() + flush_scheduled_work() ->
  cancel_delayed_work_sync().

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Duncan Sands <duncan.sands@free.fr>
Cc: linux-usb@vger.kernel.org

drivers/usb/host/ohci-hcd.c

@@ -901,7 +901,8 @@ static void ohci_stop (struct usb_hcd *hcd)
 
 	ohci_dump (ohci, 1);
 
-	flush_scheduled_work();
+	if (quirk_nec(ohci))
+		flush_work_sync(&ohci->nec_work);
 
 	ohci_usb_reset (ohci);
 	ohci_writel (ohci, OHCI_INTR_MIE, &ohci->regs->intrdisable);