be2net: swap only first 2 fields of mcc_wrb

Only the first two fields of mcc wrb - embedded, payload_len
need to be cpu_to_le32() swapped while issuing a cmd to the hw.
The fields tag0, tag1 are opaque and returned back to cpu as is...

Signed-off-by: Sathya Perla <sathyap@serverengines.com>
Signed-off-by: David S. Miller <davem@davemloft.net>