test: fix typeof comparison

The typeof operator returns a string. Compare to the string 'undefined'
and not the value undefined.

PR-URL: #37924
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

test/parallel/test-assert-calltracker-report.js

@@ -19,7 +19,7 @@ callsfoo();
 
 // Ensures that foo was removed from the callChecks array after being called the
 // expected number of times.
-if (typeof tracker.report()[0] === undefined) {
+if (typeof tracker.report()[0] === 'undefined') {
   process.exit(1);
 }