[8.x] Revert "fs: fix options.end of fs.ReadStream()"

This reverts commit b343cb60.

Some people were relying on the behavior of this.start being able to be undefined, whereas after the change it is being set to 0.

Refs: https://github.com/nodejs/node/issues/19240 Refs: https://github.com/nodejs/node/pull/18121