be2net: avoid unncessary swapping of fields in eth_tx_wrb

The 32-bit fields of a tx-wrb are little endian. The driver is currently
using be_dws_le_to_cpu() routine to swap (cpu to le) all the fields of
a tx-wrb. So, the rsvd field is also unnecessarily swapped.

This patch fixes this by individually swapping the required fields.
Also, the type of the fields in eth_tx_wrb{} is now changed to __le32
from u32 to avoid sparse warnings.

Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>