Remove leftover diagnostic that dumps generated class from test/jdk/java/io/Serializable/records/SerialPersistentFieldsTest.java

At one point it was useful to be able to inspect the generated bytecode using javap, but it was noticed recently for a different reason that the output file is always R1.class, which is clearly wrong. Anyway, this can simply be removed.

--- a/test/jdk/java/io/Serializable/records/SerialPersistentFieldsTest.java
+++ b/test/jdk/java/io/Serializable/records/SerialPersistentFieldsTest.java
@@ -32,14 +32,12 @@
 
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
-import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
 import java.io.ObjectStreamClass;
 import java.io.ObjectStreamField;
 import java.io.Serializable;
-import java.io.UncheckedIOException;
 import java.lang.reflect.Field;
 import java.lang.reflect.Modifier;
 import java.math.BigDecimal;
@@ -229,13 +227,6 @@
         ClassReader reader = new ClassReader(classBytes);
         ClassWriter writer = new ClassWriter(reader, COMPUTE_MAXS | COMPUTE_FRAMES);
         reader.accept(new SerialPersistentFieldsVisitor(writer, spf), 0);
- try {
- FileOutputStream fos = new FileOutputStream("R1.class");
- fos.write(writer.toByteArray());
- fos.close();
- } catch (IOException ioe) {
- throw new UncheckedIOException(ioe);
- }
         return writer.toByteArray();
     }