detokenize.c: remove macro READ_COEFF
detokenize.c: remove macro READ_COEFF

This wrapper isn't needed anymore now that cdf has been merged.

Change-Id: I88a7e83b4b406b2be3f2e0365dc5185ccde87056

GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom