bnx2x: fill in sane dump flag information

bnx2x did not set dump->version in its .get_dump_flag() method.
Let's set it to BNX2X_DUMP_VERSION. It's not a particularly nice
number (0x50acff01 currently), but at least it's something
deterministic.

dump->flag should report the value previously set using ethtool -W.

Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>