USB: usblp: Use correct DMA address in case of probe error

Looks like the error path had a copy-paste error. The normal exit path
uses correct URB already.
Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/class/usblp.c

@@ -1003,7 +1003,7 @@ static int usblp_probe(struct usb_interface *intf,
 				usblp->writebuf, usblp->writeurb->transfer_dma);
 		if (usblp->readbuf)
 			usb_buffer_free (usblp->dev, USBLP_BUF_SIZE,
-				usblp->readbuf, usblp->writeurb->transfer_dma);
+				usblp->readbuf, usblp->readurb->transfer_dma);
 		kfree(usblp->statusbuf);
 		kfree(usblp->device_id_string);
 		usb_free_urb(usblp->writeurb);