fs: improve fs.watch ENOSPC error message

Providing `No space left on device` is misleading in this case.
Replace it with something that describes it more accurately.

Refs: https://stackoverflow.com/questions/22475849/node-js-error-enospc/32600959

PR-URL: https://github.com/nodejs/node/pull/21846


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>