replace usage of Buffer.from with Buffer.alloc

test/interop/interop_client.js

@@ -49,10 +49,10 @@ var ECHO_TRAILING_KEY = 'x-grpc-test-echo-trailing-bin';
 /**
  * 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;
 }