suppress warning

    src/dump.c:509:3: warning: variable 'result' is used uninitialized whenever switch default is taken [-Wsometimes-uninitialized]
      default:
      ^~~~~~~
    src/dump.c:512:7: note: uninitialized use occurs here
      if (result < 0) {
          ^~~~~~
    src/dump.c:480:13: note: initialize the variable 'result' to silence this warning
      int result;
                ^
                 = 0