make the comments a bit better

Author: SylvainJuge

instrumentation/internal/internal-lambda/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/internal/lambda/LambdaTransformer.java

@@ -30,6 +30,9 @@ public static byte[] transform(byte[] classBytes, String slashClassName, Class<?
     }
 
     try {
+      // The 'targetClass' needs to be non-null as it is used in Java9LambdaClassFileTransformer
+      // to get a reference to the jpms module. However, a null value must be passed to the
+      // underlying transformer as this code is called when the lambda is defined.
       byte[] result =
           transformer.transform(
               targetClass.getClassLoader(), slashClassName, targetClass, null, classBytes);

javaagent-tooling/src/main/java/io/opentelemetry/javaagent/tooling/LambdaClassFileTransformer.java

@@ -29,7 +29,7 @@ public byte[] transform(
 
     // lambda instrumentation happens only when the lambda is defined, thus the classBeingRedefined
     // must be null otherwise we get a partial instrumentation, for example virtual fields are not
-    // properly applied. This parameter is however used in Java9LambdaClassFileTransformer.
+    // properly applied.
     return delegate.transform(loader, className, null, null, classfileBuffer);
   }
 }