IRQ FLAG rework saves 16bytes

[rob-w]

rob-w@f5548c4

is this something this project would use ?
Bascily reworked the irq testing in this section to direct bit testing, which saves 16bytes in my compile. I just wonder if such change ( logic and form ) is something the project would adopt ?
any suggestion about form and style are welcome.

*** beware this code is not tested on the hardware yet, but compiles***
cheers rob

[prokrypt]

I just tested it on my radio and it did not immediately explode, so it's good to go! 🎉