HO-DirAC: wrong index for diffusenes in the rendering
### Basic info
- Commit SHA: main
- Platform:
### Bug description
HO-DirAC accesses the diffusenes in the subframe rendering routine via the DirAC read index, this index at this point is already incremented to point at the next subframe after the currently processed one
### Ways to reproduce
(Clear steps or refer to a failing automated test, e.g. with a pipeline link)
similar as #393
<!--- Below are labels that will be added but are not shown in description. This is a template to help fill them.
Add further information to the first row and remove and add labels as necessary. -->
issue