There is a copy and paste error so we have "rx" where "tx" was intended
in the priv->tx[] array.

Fixes: f5cedc84 ("gve: Add transmit and receive support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Catherine Sullivan <csully@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>