vp9_filter: restore vp9_bilinear_filters alignment

Cherry pick https://chromium-review.googlesource.com/276889

This fixes failure caused by crash in the remoting test
VideoDecoderVp9Test.VideoEncodeAndDecode.

TBR=johannkoenig@chromium.org

Review URL: https://codereview.chromium.org/1182093002
1 file changed