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

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: <stable@vger.kernel.org>
Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>
Link: https://patch.msgid.link/20260213164340.77272-2-fourier.thomas@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>