bnx2x: remove zeroing of dump data buffer

There is no need to initialize the dump data with zeros.
data is allocated with vzalloc, so it's already zero-filled.

More importantly, the memset is harmful, because dump->len (the length
requested by userspace) can be bigger than the allocated buffer (whose
size is determined by asking the driver's .get_dump_flag method).

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