Blender Git Loki

Fix T44268: Particles: too many virtual parents + non-100 display% = crash

Issue was caused by mismatched logic in counting child/parent particles in
job initialization and actual job execution. Confusion here came from mixed
usage of psys->renderdata and G.is_rendering.

We need to get rid of G.is_rendering and use eval_ctx if it's really needed,
but we also might just use psys->renderdata check since it's expected psys
to have this structure anyway.