Net, libertas: Resolve memory leak in if_spi_host_to_card()

If we hit the default case in the switch in if_spi_host_to_card() we'll leak
the memory we allocated for 'packet'. This patch resolves the leak by freeing
the allocated memory in that case.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Acked-by: Dan Williams <dcbw@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/libertas/if_spi.c

@@ -995,6 +995,7 @@ static int if_spi_host_to_card(struct lbs_private *priv,
 		spin_unlock_irqrestore(&card->buffer_lock, flags);
 		break;
 	default:
+		kfree(packet);
 		netdev_err(priv->dev, "can't transfer buffer of type %d\n",
 			   type);
 		err = -EINVAL;