hw/net: fsl_etsec: Tx padding length should exclude CRC

As the comment of tx_padding_and_crc() says: "Never add CRC in QEMU",
min_frame_len should excluce CRC, so it should be 60 instead of 64.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Message-Id: <20210316081505.72898-1-bmeng.cn@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

hw/net/fsl_etsec/rings.c

@@ -259,7 +259,7 @@ static void process_tx_bd(eTSEC         *etsec,
                 || etsec->regs[MACCFG2].value & MACCFG2_PADCRC) {
 
                 /* Padding and CRC (Padding implies CRC) */
-                tx_padding_and_crc(etsec, 64);
+                tx_padding_and_crc(etsec, 60);
 
             } else if (etsec->first_bd.flags & BD_TX_TC
                        || etsec->regs[MACCFG2].value & MACCFG2_CRC_EN) {