Remove dead file from Makefile.
Remove dead file from Makefile.

sideeffects/HoudiniEngineForMaya,sideeffects/HoudiniEngineForMaya,pokyfudywise/HoudiniEngineForMaya,sonictk/HoudiniEngineForMaya,sonictk/HoudiniEngineForMaya,pokyfudywise/HoudiniEngineForMaya,sideeffects/HoudiniEngineForMaya,pokyfudywise/HoudiniEngineForMaya,sonictk/HoudiniEngineForMaya