Removed unused variable warnings

Change-Id: I6e5e921f03dc15a72da89a457848d519647677a3

vp8/decoder/decodemv.c

@@ -529,7 +529,9 @@ void vp8_decode_mode_mvs(VP8D_COMP *pbi)
 
         while (++mb_col < pbi->common.mb_cols)
         {
+#if CONFIG_ERROR_CONCEALMENT
             int mb_num = mb_row * pbi->common.mb_cols + mb_col;
+#endif
             /*read_mb_modes_mv(pbi, xd->mode_info_context, &xd->mode_info_context->mbmi, mb_row, mb_col);*/
             if(pbi->common.frame_type == KEY_FRAME)
                 vp8_kfread_modes(pbi, mi, mb_row, mb_col);

vp8/decoder/decodframe.c

@@ -350,8 +350,6 @@ FILE *vpxlog = 0;
 static void
 decode_mb_row(VP8D_COMP *pbi, VP8_COMMON *pc, int mb_row, MACROBLOCKD *xd)
 {
-
-    int i;
     int recon_yoffset, recon_uvoffset;
     int mb_col;
     int ref_fb_idx = pc->lst_fb_idx;

vp8/encoder/ethreading.c

@@ -120,8 +120,6 @@ THREAD_FUNCTION thread_encoding_proc(void *p_data)
                 // for each macroblock col in image
                 for (mb_col = 0; mb_col < cm->mb_cols; mb_col++)
                 {
-                    int seg_map_index = (mb_row * cm->mb_cols);
-
                     if ((mb_col & (nsync - 1)) == 0)
                     {
                         while (mb_col > (*last_row_current_mb_col - nsync) && *last_row_current_mb_col != cm->mb_cols - 1)