Audio : Fix minor comments in r_submix module am: 7770c158 am: f0506fad...

Audio : Fix minor comments in r_submix module am: 7770c158 am: f0506fad am: 41d85448 am: 2d057fc8 am: 73d4d4c3

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/2664716



Change-Id: I1e88696b847e7cacc374a48feeae367e4b4353a9
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>