In the following patches the RIF's configuration function is going to
expect a RIF struct with all the necessary information.

Therefore, allocate the RIF just before it's configured to the device.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>