sonivox: Fix global buffer overflow in WT_Interpolate am: 429f610b46 am: 60a0ec12ea

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/sonivox/+/15914668

Change-Id: Ib5773a3a2039a9f70c4e52d70bd4929aa6f3bc4b