USB: repair USBDEVFS_CONNECT ioctl

For as long as I've known about it, the USBDEVFS_CONNECT ioctl hasn't
done what it's supposed to.  The current code reprobes _all_ the
unbound USB interfaces; this patch (as1021) makes it reprobe only the
interface for which it was called.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/core/devio.c

@@ -1373,9 +1373,10 @@ static int proc_ioctl(struct dev_state *ps, struct usbdevfs_ioctl *ctl)
 
 	/* let kernel drivers try to (re)bind to the interface */
 	case USBDEVFS_CONNECT:
-		usb_unlock_device(ps->dev);
-		retval = bus_rescan_devices(intf->dev.bus);
-		usb_lock_device(ps->dev);
+		if (!intf->dev.driver)
+			retval = device_attach(&intf->dev);
+		else
+			retval = -EBUSY;
 		break;
 
 	/* talk directly to the interface's driver */