Fix FizzleFade effect

The CRT hack caused the FizzleFade effect to be skipped, thanks
to that function writing directly to the screen surface (as opposed
to screenBuffer, which is what crt.cpp expects things to be written
to)

additional notes:

* FizzleFade was used for the "fizzle to red upon death" effect, among other things.

* I left in the copy to screen after the copy to screenBuffer to preserve correct behavior with vanilla sdl (i.e. making sure it continues to work when you remove the aspect ratio hack)