src: use only one tracing write fs req at a time

Concurrent writes to the same fd are generally not ideal,
since it’s not generally guaranteed that data from those
writes will end up on disk in the right order.

PR-URL: https://github.com/nodejs/node/pull/21867


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Eugene Ostroukhov <eostroukhov@google.com>
Reviewed-By: Ali Ijaz Sheikh <ofrobots@google.com>