net: ethernet: ec_bhf: Fix dma_free_coherent() dma handle

dma_free_coherent() in error path takes priv->rx_buf.alloc_len as
the dma handle. This would lead to improper unmapping of the buffer.

Change the dma handle to priv->rx_buf.alloc_phys.

Fixes: 6af55ff52b02 ("Driver for Beckhoff CX5020 EtherCAT master module.")
Cc: <[e-mail]>
Signed-off-by: Thomas Fourier <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

drivers/net/ethernet/ec_bhf.c

···
 
 error_rx_free:
 	dma_free_coherent(dev, priv->rx_buf.alloc_len, priv->rx_buf.alloc,
-			  priv->rx_buf.alloc_len);
+			  priv->rx_buf.alloc_phys);
 out:
 	return err;
 }