replace usage of Buffer.from with Buffer.alloc

test/performance/benchmark_server.js

@@ -44,10 +44,10 @@ var serviceProto = grpc.loadPackageDefinition(protoPackage).grpc.testing;
 /**
  * Create a buffer filled with size zeroes
  * @param {number} size The length of the buffer
- * @return {Buffer} The Buffer.from
+ * @return {Buffer} The New Buffer
  */
 function zeroBuffer(size) {
-  var zeros = Buffer.from(size);
+  var zeros = Buffer.alloc(size);
   zeros.fill(0);
   return zeros;
 }