Cleanup transform pruning
Cleanup transform pruning

BUG=aomedia:448

Change-Id: If02808e3e27bf7dcb8dfdcd6899ed78a96a8fd44

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