Input: acecad - fix a memory leak in usb_acecad_probe error path

Add a missing usb_free_urb() in usb_acecad_probe() error path.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/tablet/acecad.c b/drivers/input/tablet/acecad.c
index aea9a93..d94f7e9 100644
--- a/drivers/input/tablet/acecad.c
+++ b/drivers/input/tablet/acecad.c
@@ -229,12 +229,13 @@
 
 	err = input_register_device(acecad->input);
 	if (err)
-		goto fail2;
+		goto fail3;
 
 	usb_set_intfdata(intf, acecad);
 
 	return 0;
 
+ fail3:	usb_free_urb(acecad->irq);
  fail2:	usb_free_coherent(dev, 8, acecad->data, acecad->data_dma);
  fail1: input_free_device(input_dev);
 	kfree(acecad);