After a fail, you can still drive your car back to it's normal place of store, be it your drive or a lock up garage. What you can't do is drive it to Tesco's and do your weekly shopping.
But I thought the regs stated that you could drive the car to a place of repair, which can include your home - the implication being that you are taking it onwards in order to repair it. I wouldn't think that would include just driving it home. Admittedly though I can't see how anyone could prove either way that your home was or was not a place of repair - " Show me your screwdrivers sir" "Erm, I have a hammer, does that count?"
Don't suppose it matters though, as regardless of what the MOT regs say, it would be down to the police to decide - at any time not just when returning from an MOT, passed or failed - if your car was unroadworthy.