Fix device queue length which was disabled because PostProcess was not called in the completion path. This is a regression in the vioscsi.c sources due to change https://github.com/YanVugenfirer/kvm-guest-drivers-windows/commit/28e5374671e172448b00b3701aea7554fec8310e.
Read driver controls from registry. This enables us to run with COM logging in production so we can get more information on a bug where vioscsi builds all three queues on the same GPA.
Move some debug prints to verbose so they won't overflow the log.