DLS: fix loop calculation for 16-bit am: 97f70ed81d

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/sonivox/+/18349826

Change-Id: I84d8411e9bd0c6e5d59a4ddccf2f8a9ed15c2918
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>