MSACM: implement honouring of driver priority and enabled status at load time

[Mike McCormack]

Alex Villací­s Lasso wrote:

> +                                }
> +                            }
> +                        }
> +                    }
> +                }
> +            }
> +        }
> +    }
> +}

Hmm.  A 100 line function with 10 levels of indent...

Any chance of rewriting this to reduce the level of indent?  Try using 
some helper functions or return early.  You might understand it all 
well, but this kind of code is difficult to follow and maintain.

Mike