cosmetics & warnings

- remove some unused functions
- move global arrays from data to read only section
- explicitly cast malloc returns; not specifically necessary, but helps
  show intent
- miscellaneous formatting

Change-Id: Ib15fe5b37fe6c29c369ad928bdc3a7290cd13c84

src/enc/analysis.c

@@ -35,7 +35,7 @@ static void SmoothSegmentMap(VP8Encoder* const enc) {
   const int w = enc->mb_w_;
   const int h = enc->mb_h_;
   const int majority_cnt_3_x_3_grid = 5;
-  uint8_t* tmp = (uint8_t*)malloc(w * h * sizeof(uint8_t));
+  uint8_t* const tmp = (uint8_t*)malloc(w * h * sizeof(uint8_t));
 
   if (tmp == NULL) return;
   for (y = 1; y < h - 1; ++y) {