T tracer tools: fix memory leaks, clang warnings

- Fix memory leaks detected by ASan
- Initialize variables that are flagged by compiler
- C struct initializer: x:y needs to be .x=y

common/utils/T/check_vcd.c

@@ -256,7 +256,9 @@ int main(int argc, char *argv[])
       err("%s is not correct in T_messages.txt", name);
     i++;
   }
+  free(l);
   fclose(in);
+  free_database(database);
   if (i != last_fun + 1) err("VCD FUNCTIONS wrong in T_messages.txt");
 
   return 0;