Fix error in VideoFileRenderer_nativeI420Scale.
Fix error in VideoFileRenderer_nativeI420Scale.

Check for destination buffer size was incorrect.

BUG=webrtc:6545

Review-Url: https://codereview.webrtc.org/2563563003
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#15478}

ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc