USB: usbdevfs: restore warning for nonsensical flags

If we filter flags before they reach the core we need to generate our
own warnings.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Fixes: 0cb54a3e47cb ("USB: debugging code shouldn't alter control flow")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/core/devio.c

@@ -1697,6 +1697,11 @@ static int proc_do_submiturb(struct usb_dev_state *ps, struct usbdevfs_urb *uurb
 		u |= URB_NO_INTERRUPT;
 	as->urb->transfer_flags = u;
 
+	if (!allow_short && uurb->flags & USBDEVFS_URB_SHORT_NOT_OK)
+		dev_warn(&ps->dev->dev, "Requested nonsensical USBDEVFS_URB_SHORT_NOT_OK.\n");
+	if (!allow_zero && uurb->flags & USBDEVFS_URB_ZERO_PACKET)
+		dev_warn(&ps->dev->dev, "Requested nonsensical USBDEVFS_URB_ZERO_PACKET.\n");
+
 	as->urb->transfer_buffer_length = uurb->buffer_length;
 	as->urb->setup_packet = (unsigned char *)dr;
 	dr = NULL;