[patch 2/2 net-next] mediatek: unlock on error in mtk_tx_map()

[Dan Carpenter]

There was a missing unlock on the error path.

Fixes: 656e705243fd ('net-next: mediatek: add support for MT7623 ethernet')
Signed-off-by: Dan Carpenter <dan.carpen...@oracle.com>

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c 
b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 9759fe5..c2c2e206 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -661,6 +661,8 @@ err_dma:
                itxd = mtk_qdma_phys_to_virt(ring, itxd->txd2);
        } while (itxd != txd);
 
+       spin_unlock_irqrestore(&eth->page_lock, flags);
+
        return -ENOMEM;
 }