Fix an issue in set_refs()

Scale factor for second ref frame wasn't assigned in the code.

Change-Id: I6ef3f3f71bd652a879ad847369c54c744782ea37

vp9/decoder/vp9_decodframe.c

@@ -990,6 +990,8 @@ static void set_refs(VP9D_COMP *pbi, int block_size, int mb_row, int mb_col) {
       // Select the appropriate reference frame for this MB
       const int second_fb_idx = cm->active_ref_idx[mbmi->second_ref_frame - 1];
       const YV12_BUFFER_CONFIG *second_cfg = &cm->yv12_fb[second_fb_idx];
+      xd->scale_factor[1]    = cm->active_ref_scale[mbmi->second_ref_frame - 1];
+      xd->scale_factor_uv[1] = cm->active_ref_scale[mbmi->second_ref_frame - 1];
       setup_pred_block(&xd->second_pre, second_cfg, mb_row, mb_col,
                        &xd->scale_factor[1], &xd->scale_factor_uv[1]);
       xd->corrupted |= second_cfg->corrupted;