Call MPxTransform::compute() from AssetNode::compute()
Call MPxTransform::compute() from AssetNode::compute()

This fixes evaluation issues related to transforms.

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