Correct some usages of subpel/fullpel conversion

Change-Id: I8b2af6047f96e2578b78a73e8df855f810e26a1e
diff --git a/av1/encoder/nonrd_pickmode.c b/av1/encoder/nonrd_pickmode.c
index ecf00e2..71e457e 100644
--- a/av1/encoder/nonrd_pickmode.c
+++ b/av1/encoder/nonrd_pickmode.c
@@ -159,9 +159,7 @@
   x->mv_limits = tmp_mv_limits;
   *tmp_mv = x->best_mv;
   // calculate the bit cost on motion vector
-  MV mvp_full;
-  mvp_full.row = tmp_mv->as_mv.row * 8;
-  mvp_full.col = tmp_mv->as_mv.col * 8;
+  MV mvp_full = get_mv_from_fullmv(&tmp_mv->as_fullmv);
 
   *rate_mv = av1_mv_bit_cost(&mvp_full, &ref_mv, x->nmv_vec_cost,
                              x->mv_cost_stack, MV_COST_WEIGHT);