DO NOT MERGE - SoftVPX: fix nFilledLen overflow am: b7ba49c1a0  -s ours am: c7dd19198c am: 3cb33198d6 am: baba64dd05  -s ours am: aad3552a45
am: bdb5802757

Change-Id: I04d6716461322d00f1241b9f4f1ff684ac3ed72a