net: gemini: fix memory leak

cppcheck report:
[drivers/net/ethernet/cortina/gemini.c:543]: (error) Memory leak: skb_tab
Signed-off-by: NIgor Pylypiv <igor.pylypiv@gmail.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/cortina/gemini.c

@@ -540,6 +540,7 @@ static int gmac_setup_txqs(struct net_device *netdev)
 
 	if (port->txq_dma_base & ~DMA_Q_BASE_MASK) {
 		dev_warn(geth->dev, "TX queue base it not aligned\n");
+		kfree(skb_tab);
 		return -ENOMEM;
 	}