extract_unity_shaders: Note fog in CRC comment & long filenames
extract_unity_shaders: Delay fog until all headers have been processed

Creating the fog variant as soon as I hit the shader assembly could
cause the headers to be incomplete if some of the headers came after the
assembly. Create the fog variants after parsing is complete to ensure
all headers are present.
extract_unity_shaders: Remove args where no longer needed in callchain

This basically reverts 4267ee61bd98df6f94501f943b953cbe712a0c52, as it
is no longer required now that the fog is processed after parsing.