fix unit tests for passthru

src/test/01-Basic/215-chugraph-passthrough.ck

@@ -13,5 +13,5 @@ Step step => Node node => blackhole;
 1::samp => now;
 
 // check if equal (or at least equal enough)
-if( Math.equal(.5, step.last() ) )
+if( Math.equal(.5, node.last() ) )
    <<< "success" >>>;

src/test/01-Basic/216-chugen-passthrough.ck

@@ -1,11 +1,19 @@
-class Crash extends Chugen {
-    fun float tick(float v) {
+// verify basic Chugen passthru
+class PassThru extends Chugen
+{
+    fun float tick(float v)
+    {
         return v;
     }
 }
 
-SinOsc s => Crash c => dac;
-440.0 => s.freq;
-1::second => now;
+// patch in the Node
+Step step => PassThru node => blackhole;
+// set step
+.5 => step.next;
+// let time pass
+1::samp => now;
 
-<<< "success" >>>;
+// check if equal (or at least equal enough)
+if( Math.equal(.5, node.last() ) )
+   <<< "success" >>>;