report: fix build warning in node_report.cc

Fixes `maybe-uninitialized` build warning in `src/node_report.cc`.

PR-URL: https://github.com/nodejs/node/pull/26265


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>