(index-prio) Don't increment readItems counter when the output buffer is full

This behavior was causing the reader to sometimes discard trailing entries in the list.

code/index/index-reverse/java/nu/marginalia/index/PrioIndexEntrySource.java

@@ -68,7 +68,7 @@ public class PrioIndexEntrySource implements EntrySource {
         var outputBuffer = buffer.asByteBuffer().order(ByteOrder.LITTLE_ENDIAN);
         outputBuffer.clear();
 
-        while (readItems++ < numItems && outputBuffer.hasRemaining()) {
+        while (outputBuffer.hasRemaining() && readItems++ < numItems) {
             fillReadBuffer();
 
             int rank;