It is a required field for all TX_CREATE cmd versions > 0.
This fixes a driver initialization failure, caused by recent SH-R Firmwares
(versions > 10.0.639.0) failing the TX_CREATE cmd when if_id field is
not passed.
Signed-off-by: Sathya Perla <sathya.perla@emulex.com> Signed-off-by: David S. Miller <davem@davemloft.net>