Fix for bridging with tg3 on 2.4.20

If you ever need to do bridging or perhaps multicast in Linux 2.4.20
on a DL320-G2 or other machine with a Broadcom NIC, you may need to
edit /usr/src/linux/drivers/net.tg3.c. Go to line 6161 (it says "if
(tp->pci_chip_rev_id == CHIPREV_ID_5700_B0)") and comment that line
out, like this:

/* if (tp->pci_chip_rev_id == CHIPREV_ID_5700_B0) */

Leave the line just below it ("tp->tg3_flags |=
TG3_FLAG_BROKEN_CHECKSUMS;") active (don't comment it out).

There is a patch out on the net for the "broken checksum bug" but it
did not work for me (patch reports 'malformed' error at line 14). This
worked. I don't recommend doing it unless you have a problem, though,
because I'm not sure which Broadcom NICs are affected and I'm not sure
what side effects commenting that line out may have.