Scene Particle preview shows only the particle count for the parent system, even if a sub emitter is selected.

Repro steps.
1. Open ParticleCount scene from attached project.
2. Select ParticleSystem from the hierarchy and look at the scene view.
3. In the particle effect panel, particle count shows as 1.
4. try selecting the sub emitter of the Particle System
5. In the scene view, the particle count still shows as 1.

Expected outcome: each particle system to display its own particle count when selected, regardless of where it is parented.

Notes:
- Not a regression, present in Version 5.3.1f1 (cc9cbbcc37b4)
- Just setting a particle system as a child of another (without being a sub emitter) also exhibits the same behaviour.