fs: unify style in preprocessSymlinkDestination

Removes the else after return to match rest of the style of
the function.

PR-URL: https://github.com/nodejs/node/pull/33496


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>