fs: do not emit 'finish' before 'open' on write empty file

'finish' could previously be emitted before the file has been
created when ending a write stream without having written any
data.

Refs: https://github.com/expressjs/multer/issues/238

PR-URL: https://github.com/nodejs/node/pull/29930


Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>