Create all instances of InstancedStaticMeshComponent at once

[anonymous_user_88d57b37]

solved: was missing the PerInstanceSMData:

	TArray<FInstancedStaticMeshInstanceData> smdata;
	for (int i = 0; i < pointCount; i++)
		auto NewInstanceData = new(smdata) FInstancedStaticMeshInstanceData();
	StreamComponent->PerInstanceSMData = smdata;