Simplify RecordingStream bulk read

The forced loop-reading was inherited from JMC, but we don't know its purpose.
The simpler one-shot impl passes our tests and the output JFR opens in IntelliJ.

PS. remove unncessary ByteArray clone.

src/main/java/org/openjdk/jmc/flightrecorder/testutils/parser/RecordingStream.java

@@ -64,17 +64,13 @@ byte[] stopRecordingWrites() {
     }
 
     public void read(byte[] buffer, int offset, int length) throws IOException {
-        while (length > 0) {
-            int read = delegate.read(buffer, offset, length);
-            if (read == -1) {
-                throw new IOException("Unexpected EOF");
-            }
-            if (isRecordingWrites) {
-                toBytesStream.write(buffer, offset, read);
-            }
-            offset += read;
-            length -= read;
-            position += read;
+        int read = delegate.read(buffer, offset, length);
+        if (read == -1) {
+            throw new IOException("Unexpected EOF");
+        }
+        position += read;
+        if (isRecordingWrites) {
+            toBytesStream.write(buffer, offset, read);
         }
     }
 

src/main/java/tools/profiler/jfr/converter/CheckpointEvent.java

@@ -46,7 +46,7 @@ public CheckpointEvent(byte[] eventPayload, long eventType, MetadataEvent metada
         if (eventType != 1) {
             throw new IOException("Unexpected event type: " + eventType + " (should be 1)");
         }
-        this.payload = ByteBuffer.wrap(eventPayload.clone());
+        this.payload = ByteBuffer.wrap(eventPayload);
         this.stream = new RecordingStream(new ByteArrayInputStream(eventPayload));
         this.metadata = metadata;
         this.listener = listener;