Blender Git Loki

Fix T84588: Cache access in rna_Particle_uv_on_emitter

The function `rna_Particle_uv_on_emitter` did not handle the case where
`particle->num_dmcache` was `DMCACHE_ISCHILD`. This resulted in an
incorrect offset for the `mtface` pointer. The commit checks for the
case and sets the offset accordingly, similar to existing code in
e.g. `particle_calculate_parent_uvs`.

Reviewed By: JacquesLucke

Differential Revision: https://developer.blender.org/D10072