crypto: move _randomBytes call out of handleError funct

This commit moves the _randomBytes function call out of the handleError
function, which now it takes in an error and a buf object as its
parameters.

PR-URL: #28318
Reviewed-By: Yongsheng Zhang <zyszys98@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: James M Snell <jasnell@gmail.com>

lib/internal/crypto/random.js

@@ -51,7 +51,7 @@ function randomBytes(size, cb) {
 
   const buf = Buffer.alloc(size);
 
-  if (!cb) return handleError(buf, 0, size);
+  if (!cb) return handleError(_randomBytes(buf, 0, size), buf);
 
   const wrap = new AsyncWrap(Providers.RANDOMBYTESREQUEST);
   wrap.ondone = (ex) => {  // Retains buf while request is in flight.
@@ -77,7 +77,7 @@ function randomFillSync(buf, offset = 0, size) {
     size = assertSize(size, elementSize, offset, buf.byteLength);
   }
 
-  return handleError(buf, offset, size);
+  return handleError(_randomBytes(buf, offset, size), buf);
 }
 
 function randomFill(buf, offset, size, cb) {
@@ -115,8 +115,7 @@ function randomFill(buf, offset, size, cb) {
   _randomBytes(buf, offset, size, wrap);
 }
 
-function handleError(buf, offset, size) {
-  const ex = _randomBytes(buf, offset, size);
+function handleError(ex, buf) {
   if (ex) throw ex;
   return buf;
 }