fs: make 'end' work with ReadStream without 'start'
fs: make 'end' work with ReadStream without 'start'

Make `fs.createReadStream({ end: 42 })` work.

Before this commit, it worked only when used like this:
`fs.createReadStream({ start: 0, end: 42 })` - only when `start` was specified
by the caller.

Fixes #4423.

dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node