USB HID: avoid flush_scheduled_work()

This patch (as914) replaces a call to flush_scheduled_work() with
cancel_work_sync(), in order to help avoid potential deadlocks.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
index d91b9da..093abb5 100644
--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -956,7 +956,7 @@
 	usb_kill_urb(usbhid->urbctrl);
 
 	del_timer_sync(&usbhid->io_retry);
-	flush_scheduled_work();
+	cancel_work_sync(&usbhid->reset_work);
 
 	if (hid->claimed & HID_CLAIMED_INPUT)
 		hidinput_disconnect(hid);