Refactor: build_inter_predictors_single_buf
Refactor: build_inter_predictors_single_buf

Call calc_subpel_params instead of repeat those lines.

Change-Id: Ie0746660ce19603bde761869e3873d37b29a0389

GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom