Replace memcpy with vpx_memcpy

Also removed obselete comment

Change-Id: Iae1664777d76383639c637ee786e0d50fc45819a

vp9/common/vp9_convolve.c

@@ -282,7 +282,7 @@ void vp9_convolve_copy_c(const uint8_t *src, ptrdiff_t src_stride,
   int r;
 
   for (r = h; r > 0; --r) {
-    memcpy(dst, src, w);
+    vpx_memcpy(dst, src, w);
     src += src_stride;
     dst += dst_stride;
   }

vp9/common/vp9_findnearmv.c

@@ -54,7 +54,7 @@ void vp9_append_sub8x8_mvs_for_idx(VP9_COMMON *cm, MACROBLOCKD *xd,
 
   dst_list[1].as_int = 0;
   if (block_idx == 0) {
-    memcpy(dst_list, mv_list, MAX_MV_REF_CANDIDATES * sizeof(int_mv));
+    vpx_memcpy(dst_list, mv_list, MAX_MV_REF_CANDIDATES * sizeof(int_mv));
   } else if (block_idx == 1 || block_idx == 2) {
     int dst = 0, n;
     union b_mode_info *bmi = mi->bmi;

vp9/encoder/vp9_rdopt.c

@@ -2242,11 +2242,9 @@ static void store_coding_context(MACROBLOCK *x, PICK_MODE_CONTEXT *ctx,
   vpx_memcpy(ctx->zcoeff_blk, x->zcoeff_blk[xd->this_mi->mbmi.tx_size],
              sizeof(ctx->zcoeff_blk));
 
-  // FIXME(rbultje) does this memcpy the whole array? I believe sizeof()
-  // doesn't actually work this way
-  memcpy(ctx->tx_rd_diff, tx_size_diff, sizeof(ctx->tx_rd_diff));
-  memcpy(ctx->best_filter_diff, best_filter_diff,
-         sizeof(*best_filter_diff) * (SWITCHABLE_FILTERS + 1));
+  vpx_memcpy(ctx->tx_rd_diff, tx_size_diff, sizeof(ctx->tx_rd_diff));
+  vpx_memcpy(ctx->best_filter_diff, best_filter_diff,
+             sizeof(*best_filter_diff) * (SWITCHABLE_FILTERS + 1));
 }
 
 static void setup_pred_block(const MACROBLOCKD *xd,