benchmark: increase iteration of randomBytes case to appropriate one

Increase iteration value from 1000 to 10000 to reflect real performance
of randomBytes generation. The randomInt has no need to apply this.

Fixes:nodejs#50571

Author: Lei Shi

benchmark/crypto/randomBytes.js

@@ -5,7 +5,7 @@ const { randomBytes } = require('crypto');
 
 const bench = common.createBenchmark(main, {
   size: [64, 1024, 8192, 512 * 1024],
-  n: [1e3],
+  n: [1e4],
 });
 
 function main({ n, size }) {