Fix use of stream.write(data, encoding) in tests

For several tests I used a shortcut to write an list-of-chunks to a
stream:

    chunks.forEach(stream.write.bind(stream));

This is a quick way to make a function from a method. The problem is
that `forEach` will pass the index of the array item as a second
argument, and `write` has a second argument (buffer) `encoding`. In
Node v15, the encoding is actually checked to see if it's valid -- and
numbers are not valid buffer encodings:

    nodejs/node#33075

The fix is simply to be explicit about which arguments are passed,
rather than relying on the shortcut. This is a little more verbose,
but can still be put in line at least.

Signed-off-by: Michael Bridgen <mikeb@squaremobius.net>

test/frame.js

@@ -123,7 +123,7 @@ suite("Parsing", function() {
         bufs.push(defs.encodeMethod(f.id, 0, f.fields));
       });
 
-      partition(bufs).forEach(input.write.bind(input));
+      partition(bufs).forEach(function (chunk) { input.write(chunk); });
       frames.acceptLoop();
       if (ex) throw ex;
       return i === t.length;

test/mux.js

@@ -41,7 +41,7 @@ test("single input", function(done) {
   // not 0, it's treated specially by PassThrough for some reason. By
   // 'specially' I mean it breaks the stream. See e.g.,
   // https://github.com/isaacs/readable-stream/pull/55
-  data.forEach(input.write.bind(input));
+  data.forEach(function (chunk) { input.write(chunk); });
 
   readAllObjects(output, function(vals) {
     assert.deepEqual(data, vals);
@@ -75,7 +75,7 @@ test("single input, resuming stream", function(done) {
     return val;
   }
 
-  data.forEach(input.write.bind(input));
+  data.forEach(function (chunk) { input.write(chunk); });
 
   readAllObjects(output, function(vals) {
     assert.deepEqual([1,2,3,4,6,7,8,9], vals);
@@ -145,13 +145,13 @@ test("unpipe", function(done) {
   mux.pipeFrom(input);
 
   schedule(function() {
-    pipedData.forEach(input.write.bind(input));
+    pipedData.forEach(function (chunk) { input.write(chunk); });
 
     schedule(function() {
       mux.unpipeFrom(input);
 
       schedule(function() {
-        unpipedData.forEach(input.write.bind(input));
+        unpipedData.forEach(function(chunk) { input.write(chunk); });
         input.end();
         schedule(function() {
           // exhaust so that 'end' fires