test: replace error msg w/ template literal

test: replace error msg w/ template literal · nodejs/node@cd57d2d

Original file line number	Diff line number	Diff line change
`@@ -14,8 +14,8 @@ if (cluster.isMaster) {`
`14`	`14`	`for (let i = 0; i < workers.toStart; ++i) {`
`15`	`15`	`const worker = cluster.fork();`
`16`	`16`	`worker.on('exit', common.mustCall(function(code, signal) {`
`17`		`-assert.strictEqual(code, 0, 'Worker exited with an error code');`
`18`		`-assert.strictEqual(signal, null, 'Worker exited by a signal');`
	`17`	+assert.strictEqual(code, 0, `Worker exited with an error code: ${code}`);
	`18`	+assert.strictEqual(signal, null, `Worker exited by a signal: ${signal}`);
`19`	`19`	`}));`
`20`	`20`	`}`
`21`	`21`	`} else {`