USB: extension of anchor API to unpoison an anchor

This extension allows unpoisoning an anchor allowing drivers that
resubmit URBs to reuse an anchor for methods like resume()

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/include/linux/usb.h b/include/linux/usb.h
index 4e8654a..e896398 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -1485,6 +1485,7 @@
 extern void usb_unpoison_urb(struct urb *urb);
 extern void usb_kill_anchored_urbs(struct usb_anchor *anchor);
 extern void usb_poison_anchored_urbs(struct usb_anchor *anchor);
+extern void usb_unpoison_anchored_urbs(struct usb_anchor *anchor);
 extern void usb_unlink_anchored_urbs(struct usb_anchor *anchor);
 extern void usb_anchor_urb(struct urb *urb, struct usb_anchor *anchor);
 extern void usb_unanchor_urb(struct urb *urb);