This patch fixed errors reported in Issue 746: "dr memory VP8
encode errors" and Issue 745: "dr memory VP8 decode errors".
The "UNINITIALIZED READ" errors were fixed in x86 assembly
code. The list of files fixed is
vp8_intra_pred_uv_tm_sse2
vp8_intra_pred_uv_tm_ssse3

vp8_intra_pred_uv_ho_mmx2
vp8_intra_pred_uv_ho_ssse3

vp8_intra_pred_y_tm_sse2
vp8_intra_pred_y_tm_ssse3

vp8_intra_pred_y_ho_sse2

Change-Id: Ib6df7bf1d442077fe534edfd90e50ad16fadacdd